Digital Glossary
Digital imaging is the next, logical extension of the same type of camera and darkroom techniques that photographers have been using for 150 years. The tools used for digital imaging may appear to be different, but they are no more of a radical change than what late 19th century daguerreotypists encountered when they switched from silver plated copper sheets to glass plate negatives.
Like other disciplines, photography has its share of jargon. As photographers we "shoot" brides and kids, "bracket" these shots, and apply "Zone IV" interpretations to an image on "sheet" film that�s processed using "N+1" development. Part of the problem of understanding digital imaging concepts--like much of computing--boils down to semantics. Digital imaging uses a combination of buzzwords that have been borrowed from the printing, design, and photographic fields, liberally blended with a sprinkling of computer jargon.
Joe Farace�s book, The Digital Imaging Dictionary, is published by Allworth Press. It is available in bookstores or order directly from the publisher. You can contact them at (800) 247-6553 or their web site at: www.allworth.com
Here�s an abbreviated look at some common digital imaging terms.
Access Time: The performance of fixed or removable drives is measured by seek time or the amount of time required for the arm of a direct access storage device to position itself over the track where the required information is stored on the disc.
ADB: Apple Desktop Bus. The Mac OS communications port that is used for keyboards, mice, trackballs, graphics tablets, joysticks, and other input devices.
Alpha Channel: This is a separate image channel that is added to the traditional red, green, and blue channels and contains a value that indicates the amount of transparency for each pixel.
Analog: Information presented in continuous form, corresponding to a representation of the "real world." A traditional photographic print is an analog form, but when this same image is scanned and converted into digital form, it is made up of bits.
Archive: To copy any kind of data from the media it is currently stored on (typically a hard disk) onto a removable media cartridge or tape for back-up purposes. Archive and back-up software often compress the data to maximize the capacity of that storage media.
ASCII: American Standard Code for Information Interchange. ASCII is a standardized computer code for representing text data. The code has 96 displayed characters (characters you see on the screen) and 32 non-displayed characters (some of which you can see, others that you can�t).
Binary: A mathematical system based on the numbers one and zero. This is ideal for computers, because electrical signals can be represented by electrical current being positive and negative, on and off.
Bit: Binary digit. The smallest unit of information with which a computer can work. Computers are digital devices because they represent all data--including photographs--using numbers, or digits, that are measured in bits.
Bit Depth: This refers to the number of bits that are assigned to each pixel in an image. The more bits you have, the more photo-realistic the screen image will be. Let�s look at the typical choices in bit depth for computer screens:
1-bit: If a computer has the ability to display 1-bit per pixel, each pixel can either be black or white.
4-bit: Some computers, especially laptops, offer 4-bit video capability, which translates into 16 shades of gray or color.
8-bit: With an 8-bit color depth, you can see 256 colors or levels of gray. An 8-bit system can work well for black and white photographs, but is just barely adequate for critical evaluation of a color photograph.
16-bit: This bit depth has the potential to display 32,000 different colors. At 16-bits and above, the video signal must split into thirds, providing one each for the red, blue, and green channels. Your computer devotes 15 bits to color (5 bits per color channel) and the one remaining bit is used to overlay all these colors.
24-bit: Each pixel on a screen can handle up to 256 colors, which lets systems display 16.7 million colors. A 24-bit model provides true photographic quality.
32-bit: Often when someone is talking about 32-bit color, they really mean 24-bit. Only a few computers offer 32-bit capabilities.
Since 256 levels of gray are displayed on an 8-bit system, that�s all you really need when working with black and white digital photographs, but if you plan on working with color images, you should use a computer that has a 24-bit display.
Bitmap: There are three classes of graphic files: bitmap, metafile, and vector. A bitmap (sometimes known as "raster") is any graphic image composed of a collection of tiny individual dots or pixels--one for every point or dot on a computer screen.
BMP: Short for bitmap. A Win-dows based digital image format, BMP--often pronounced "bump"-- is really a file extension for a specific kind of bitmapped graphics file.
Bundle: Part of a software or hardware package, which may or may not be a good deal. When you purchase a product that�s packaged with a product from another company at no additional cost, the extra product is considered to be "bundled" with the main product.
Byte: Each electronic signal is one bit, but to represent more complex numbers or images, computers combine these signals into larger 8-bit groups called bytes. When 1024 (not 1000) bytes are combined, you get a kilobyte, often called K.
Calibration: A term used in Color Management Systems (CMS). Calibration stabilizes the inevitable variables in the way devices reproduces color. To produce optimum results, all color-reproducing devices must maintain a consistent, calibrated state.
CCD: A Charge-Coupled Device is the same kind of light gathering device used in flat-bed scanners, digital cameras, and even video camcorders to convert the light passing through the lens into an electronic equivalent of the original image. These images become digitized by the CCD device.
CD-ROM: Compact Disc Read Only Memory. This is a disc that resembles a musical compact disk but can contains all kinds of data--including photographs.
CD-R: Compact Disc Recordable
CD-RW: Compact Disk Re-Writable
CEPS: Color Electronic Publishing Systems
Characterization: A Color Man-agement System (CMS) term that establishes the relationship of your calibrated device to what is referred to as a device independent Reference Color Space or RCS.
Clipping Path: A path is a series of line segments connected by endpoints. Paths are created by the pen tool and can be reshaped and moved--even exported to other files or programs. Clipping paths silhouette an area to mask out the background, so only that part of the images within the path appears when the image is placed in another program or combined with another image file.
CLUT: Color Look Up Table. A table--it can be in hardware or software form--that contains information on the mixing of red, green and blue color intensity in a palette.
Compression: Compression is a method of removing unneeded data to make a file smaller without losing any data, or in the case of a photographic file, image quality. There are many techniques and technologies for compressing graphics and how well each works depends on what is more important to you: file size or image quality.
CPU: Central Processing Unit. There are two basic families of CPUs: Intel and Motorola. Intel and similar chips are used in IBM-compatible PCs, while Motorola makes the chips for Mac OS machines. How well a chip processes data is determined by how many bits of information it can process at one time. The larger the number of bits a chip can process simultaneously, the faster it can process.
DCS: Desktop Color Separation. The QuarkXPress format for defining color separated output using a personal computer.
DCT: Discrete Cosine Transform. This is an algorithm that converts data--including pixels--into sets of frequencies. The first frequencies appearing in the set are the most meaningful; the latter, are the least. For compression purposes, such as JPEG and MPEG, the latter frequencies are removed on the basis on allowable resolution loss.
Despeckle: A feature of image-editing programs, and some plug-ins (e.g. Extensis Intellihance) that detects the edges of an image--the place where significant color changes occur--and blurs a selection except the edges. This has the effect of removing noise while preserving detail.
Device Resolution: Refers to the number of dots per inch (dpi) that any given device, such as a monitor or printer, can produce. Screen resolution for computer monitors varies from 60-120dpi. Don�t confuse this with line screen, which refers to the number of lines per inch (lpi) in the screen used by printers to reproduce a photograph.
Dither: A graphics display or printing process that uses a combination of dots or textures to create the impression of a continuous tone gray scale or color image.
DOS: Disc Operating System. The official name of the Microsoft Disk Operating System is MS-DOS but is often referred to as simply DOS. The IBM-PC version is called PC-DOS, or just DOS.
DRAM: Dynamic Random Access Memory
Dynamic Range: One key feature to look for in a scanner or digital camera is its dynamic range. A scanner�s dynamic range depends on the maximum optical density that can be achieved and the number of bits captured. In simple terms, the greater the density range the better the scanner.
DVD: Digital Versatile Disc, sometimes referred to as Digital Video Disc.
EDO DRAM: Extended Data Out-put DRAM is popular in Windows based computers. EDO DRAM sends our data--even if a controller loads more data in vacant addresses.
EMF: Electromagnetic Field. If you spend more than a few hours at your computer a day you should be aware of the potential problems caused by the electromagnetic fields that computer monitors produce. All monitors emit some kind of Very Low Fre-quency (VLF) and Extremely Low Frequency (ELF) radiation, and color monitors emit more than monochromatic ones.
FAQ: Frequently Asked Questions. A term, often found on web home pages, that will lead you to a page containing the most frequently asked questions visitors to the web site may have.
FPM DRAM: Fast Page Mode DRAM is the most common type that is used in Mac OS systems because it speeds the overall readout of data but does introduce a wait state.
Gamma: All photographs have a characteristic called gamma. The amount of gamma present in an image is measured as the contrast that affects the mid-level grays (the mid tones) of an image. The good news for digital imagers is that this gamma is adjustable by most image-enhancement programs, and you aren�t stuck with the gamma that is present in the original negative or print.
Gamut: Every output device (e.g., a printer or monitor) has a range of colors that it can accurately reproduce. This range is called the gamut of the device. Every device from every manufacturer, whether it is a monitor or printer, has a unique gamut.
Gaussian Blur: Photoshop�s blurring filter gets its name from the fact that it maps revised pixel color values according to a Gaussian curve. A Gaussian curve is typically used to represent a normal or statistically probable outcome for a random distribution of events and is often shown as a bell shaped curve.
GIF: (Pronounced like the peanut butter.) Graphic Interchange Format developed by CompuServe is completely platform independent: the same bitmapped file created on a Mac OS computer is readable by a Windows graphics program. A 256 color GIF file is automatically compressed making it ideal for use on the World Wide Web.
Gigabyte: A billion bytes or (more correctly) 1024 megabytes
Gray Scale: Refers to a series of gray tones ranging from white to pure black. The more shades or levels of gray, the more accurately an image will look like a full-toned black and white photograph. Most scanners will scan from 16-256 gray levels. A gray scale image file is typically 1/3 the size of a color one.
GUI: Graphic User Interface
HTML: HyperText Markup Lan-guage, a format used on World Wide Web home pages on the Internet that uses multimedia techniques to make the web easy to browse.
Image Resolution: Refers to the amount of information stored in a photograph and is typically expressed in pixels or dots per inch (dpi). The image resolution of a photograph determines how big the file is. The important thing to remember is that the higher the image resolution, the more disk space it takes and the longer it will take to print or image.
Ink Jet: In an ink jet printer, a print head sprays one or more colors of ink onto paper to produce output, and the type of methods used to accomplish this has an effect on output quality.
Interlaced GIF: (See GIF.) The interlaced version stores rows of bitmapped data out of order: All of the even numbered rows are stored first and all of the odd rows are stored last. Interlaced GIF uses a four pass interlacing. The first pass starts at row zero and reads every eighth row of bitmap information. The second pass starts on the fourth row and reads every fourth row. The third pass starts on the second row and reads every second row while the last pass starts with the first row and reads every second row.
ISP: Internet Service Providers. Companies that offer direct access to the Internet through local or toll free telephone connections. This includes companies such as CompuServe, America Online, as well as a plethora of local operations that often provide service at a flat ("all you can eat") rate.
JPEG: An acronym for a compressed graphics format created by the Joint Photographic Experts Group, within the International Standards Organization. JPEG achieves compression by breaking an image into discrete blocks of pixels, which are then divided in half until a compression ratio of 10:1-100:1 is achieved. The greater the compression ratio, the greater loss of sharpness you can expect.
K: In the computer world, K stands for two to the 10th power, or 1024. A Kilobyte (or KB) is, therefore, not 1000 bytes but is 1024 bytes.
Layer: In image enhancement programs like Adobe Photoshop, layers are any one of several on-screen independent levels for creating separate, but cumulative, effects for an individual photograph. Layers can be manipulated independently and the sum of all the individual effects on each layer make up what you see as the final image.
LUT: Color Look Up Table. A table--it can be in hardware or software form--that contains informat
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Nikon Speedlight SB-900
Nikon Speedlight SB-900
July 1, 2008
Advanced, high-performance Speedlight for Nikon digital SLR cameras
TOKYO – Nikon Corporation is pleased to announce the introduction of the Nikon Speedlight SB-900, a new external i-TTL flash unit with advanced features. The SB-900 offers a powerful guide number of 48/157.5 (ISO 200, meters/feet) and an incredible array of creative flash functions. The SB-900 is an ideal way to solve lighting challenges and extend Nikon D-SLR creativity.
The SB-900 is a high-performance Speedlight developed as the successor to the hugely successful Nikon SB-800. Practical functionality was emphasized in designing the SB-900, especially evident when used with Nikon digital SLR cameras compatible with the Nikon Creative Lighting System. It provides a wide 17-200 mm auto zoom range (expanded from the SB-800’s 24-105mm), three illumination patterns, newly designed, streamlined operation with a full-information LCD panel, and AF-Assist illumination compatible with new-generation AF sensors. The SB-900 has an improved booster circuit for high-speed recycle time. In addition, firmware can be uploaded via a Nikon digital SLR camera—a world’s first* for flash units, assuring that the SB-900 can accept technological advancements. The SB-900 serves as the new core for the Nikon Creative Lighting System when used in combination with current Nikon digital SLRs, and it supports Advanced Wireless Lighting as a master or a remote Speedlight, inviting photographers to explore the many creative possibilities.
Additional new functions include 180 degrees of left or right head swivel, a special built-in overheat protection system and automatic filter detection for unprecedented white balance correction, even in fluorescent lighting conditions.
With the SB-900, users can enjoy all the benefits of the Nikon Creative Lighting System for both automation and comprehensive control, enabling endless lighting possibilities.
*The world’s first flash unit with a user-applied firmware update function via a digital SLR camera as of July 1, 2008 (according to research conducted by NIKON CORPORATION).
Note: Specifications, design, product name, standard accessories and release schedule may differ by country or region
Nikon Speedlight SB-900 Major Features
- Multi-step auto zoom covers wide 17-200mm zoom range (24-105mm：SB-800)
- Three illumination patterns (standard, center-weighted and even) are available to match each shooting environment
- Automatically detects Nikon FX and Nikon DX formats and selects suitable light distribution
- Improved booster circuit for high-speed recycle time: Recycle time using four AA-size batteries is almost equal to the SB-800 with five AA-size batteries
- New AF-Assist illumination covers a wide 20-105 mm focal range compatible with the new Multi-CAM3500 FX/DX AF sensor
- Firmware update via Nikon D3 and D700 is possible (world’s first*)
- Thermal Cut-out function limits the number of flashes to avoid deterioration of light emitting parts caused by continuous flash firing
- Automatically detects color filters (fluorescent or incandescent), enabling camera to control color temperature according to filter information from SB-900
- Improved switch panel for enhanced usability
- Improved GUI using a large-size LCD dot panel
- Bounce capability: tilts up to 90º, down to -7º, rotates horizontally 180º to right and left
- Advanced Wireless Lighting and versatile functions for up to three remote groups of SB-900s or other compatible Speedlight controlled through the master SB-900
- Optional Water Guard WG-AS1 (for D3), WG-AS2 (for D300), and WG-AS3 (for D700) is useful for protecting the camera's hot shoe contact when the SB-900 is mounted on these Nikon digital SLR cameras
*The world’s first flash unit firmware update function via a digital SLR camera as of July 1, 2008 (according to research conducted by NIKON CORPORATION).
Speedlight SB-900 Specifications
| Electronic construction | Automatic Insulated Gate Bipolar Transistor (IGBT) and series circuitry | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Guide number (20°C/68°F) | 34/111.5 (ISO 100, m/ft), 48/157.5 (ISO 200, m/ft) | |||||||||||||||
| Illumination pattern | Three illumination patterns: standard, even and center-weighted The light distribution angle is automatically adjusted to the camera’s image area in both FX and DX formats | |||||||||||||||
| Flash shooting distance range | 0.6 m to 20 m (2 to 66 ft) (varies depending on camera image area setting, illumination pattern, ISO sensitivity, zoom position, and lens aperture) | |||||||||||||||
| Flash mode | TTL, Auto Aperture flash, Non-TTL auto flash, Distance-priority manual flash, Manual flash, Repeating flash | |||||||||||||||
| Other functions | Test firing, monitor pre-flashes, AF-assist illuminator, and Modeling illuminator | |||||||||||||||
| Multiple flash operation | Advanced Wireless Lighting, SU-4 type wireless multiple flash | |||||||||||||||
| Compatible cameras | All cameras compatible with Nikon Creative Lighting System (other cameras can be used but functionality is reduced) | |||||||||||||||
| Flash exposure control set on the camera | Camera’s sync modes: Slow-sync, Red-eye reduction in slow-sync, Rear-curtain sync, Rear-curtain slow-sync Shooting functions: Auto FP High-Speed sync, FV Lock flash | |||||||||||||||
| Bounce capability | Flash head tilts down to -7° or up to 90° with click-stops at -7°, 0°, 45°, 60°, 75°, 90° Flash head rotates horizontally 180° to the left and right with click-stops at 0°, 30°, 60°, 90°, 120°, 150°, 180° | |||||||||||||||
| ON/OFF | Press the Power ON-OFF switch to turn the SB-900 on or off Standby function can be set | |||||||||||||||
| Power source/min. recycle time/no. of flashes (at full output) With fresh batteries (These data may vary depending on battery condition) | ||||||||||||||||
Four AA-size penlight batteries (1.5V or lower) of the following types:
* When firing the Speedlight at full output once every 30 seconds (120 seconds with lithium batteries.) | ||||||||||||||||
| Ready light | The SB-900 is fully recycled: Rear ready-light lights up and front light blinks Insufficient light for correct exposure (in i-TTL, Auto Aperture flash, Non-TTL Auto flash, or Distance-priority manual flash operations): ready-lights and front lights blink after shooting | |||||||||||||||
| Flash duration | Approx. 1/880 sec. at full output | |||||||||||||||
| Mounting foot lock lever | Provides secure attachment of SB-900 to camera’s accessory shoe using locking plate and mount pin to prevent accidental detachment. | |||||||||||||||
| Dimensions (W x H x D) | Approx. 78.0 x146.0 x 118.5 mm (3.0 x 5.7 x 4.7 in.) | |||||||||||||||
| Weight (without batteries) | Approx. 415 g (14.6 oz.) | |||||||||||||||
| Supplied accessories | Speedlight Stand AS-21, Nikon Diffusion Dome SW-13H, Color Filter Set SJ-900, Color Filter Holder SZ-2, Soft Case SS-900 | |||||||||||||||
| Optional accessories | Color Filter Set SJ-3, Water Guard WG-AS1/WG-AS2/WG-AS3, High-Performance Battery Pack SD-9, Wireless Slave Flash Controller SU-4, TTL Remote Cord SC-28/SC-29 | |||||||||||||||
Nikon D700
Digital SLR Camera Nikon D700
July 1, 2008
Nikon FX-format digital SLR – exceptional performance combined with superior mobility and functional versatility to provide serious photographers with outstanding value
D700
TOKYO – Nikon Corporation is pleased to announce the introduction of its newest FX-format digital SLR, the Nikon D700.
The D700 features an FX-format first introduced with the Nikon D3. Highly praised for its outstanding features, the D3 established a new level of professional performance in terms of overall image quality, extraordinarily low noise, ISO sensitivity range, continuous high-speed shooting, color gradation, image crispness, durability, weather-resistant operation, system versatility and more.
The new D700 incorporates an extensive array of features that boast a level of performance that is in many ways comparable to the D3. At the same time, it derives a wide range of benefits – including functionality, flexibility and operability – from the more agile D300, Nikon's flagship DX-format D-SLR.
The D700 has everything it takes to satisfy a broad spectrum of photographic needs. The 12.1-megapixel FX-format CMOS sensor with a sensing area of 36.0 x 23.9 mm; a sensitivity range of ISO 200 to 6400; continuous shooting at up to 5 frames per second (and up to 8 fps with the optional Multi-Power Battery Pack MB-D10; Nikon's exclusive 51-point AF system; Scene Recognition System for optimum autofocus, auto exposure and auto white balance detection – these are but a few of the advanced capabilities of the extraordinary new D700.
Major Features
Large image sensor, developed by Nikon; 12.1 effective megapixels
The D700 employs an FX-format CMOS image sensor with an area of 36.0mm (h) x 23.9mm (v). It provides superior picture quality throughout a wide ISO sensitivity range, with advantages that include a large pixel size to ensure a higher signal-to-noise ratio and wide dynamic range, and improved circuit layout to efficiently increase the strength of the electrical signal from pixels. High-speed, 12-channel readout enables fast continuous shooting of high-resolution images at up to 8 frames per second (with Multi-Power Battery Pack MB-D10 and Rechargeable Li-ion Battery EN-EL4a/4 or eight AA-size batteries).
Wide sensitivity range
The D700 offers an extremely wide sensitivity range of ISO 200 to 6400. It delivers extraordinary image quality at low sensitivity settings, while also delivering outstandingly low-noise characteristics at ISO settings as high as 6400. Furthermore, sensitivity can be increased to HI 0.3, HI 0.5, HI 0.7, HI 1 (ISO 12,800 equivalent), HI 2 (ISO 25,600 equivalent), or decreased to Lo 1 (ISO 100 equivalent), Lo 0.7, Lo 0.5 and Lo 0.3, to expand shooting versatility.
High-speed performance
Features a startup time of approximately 0.12 second, and a shutter release time lag of only 40 ms* – both equivalent to the flagship Nikon D3. The continuous shooting speed is up to 5 frames per second with the included Rechargeable Li-ion Battery EN-EL3e, and up to 8 fps when using the optional Multi-Power Battery Pack MB-D10 and Rechargeable Li-ion Battery EN-EL4a/4 or eight AA-size batteries. The Nikon D700 is also compliant with the next-generation high-speed UDMA CompactFlash cards, that will enable 35-Mbyte recording speed.
* Based on the new CIPA guideline established in August 2007.
EXPEED image processing
Nikon's state-of-the-art EXPEED digital image-processing incorporates remarkable intelligence and technologies accumulated and optimized throughout our long history. It makes possible a diverse range of functions that ensure superior picture quality and high-speed image processing.
Scene Recognition System
Improvements to the exclusive 1,005-pixel RGB light sensor have allowed information from the sensor to be utilized for auto exposure, auto white balance and autofocus. 3D-Tracking in AF, for example, achieved by using the Scene Recognition System, tracks subject position and automatically shifts the AF points used to match the subject's movement within the frame. This system also contributes to higher accuracy of auto exposure and auto white balance detection.
Picture Control System
Nikon's Control System enables users, from novices to professionals, to create the pictures they envision by making specific selections and adjustments to image sharpening, tone compensation, brightness, tone and saturation. Even with different cameras, when the settings are the same, you get the same picture tone. Picture Control System offers four fundamental setting options – Standard, Neutral, Vivid and Monochrome – for easy customization of image parameters.
Active D-Lighting
Active D-Lighting lets photographers choose from various intensities – Auto, High, Normal, Low or OFF (Unchanged) – prior to shooting. Instead of employing the conventional compensation method of simply expanding dynamic range, localized tone control technology is utilized to ensure proper contrast and eliminate flat images with lost highlights and shadows.
AF system with high-density 51-point AF
The D700 incorporates a Multi-CAM 3500FX autofocus sensor module featuring 51 AF points. Fifteen cross-type sensors located in the center enable subject detection with lens apertures as small as f/5.6. The functioning of the AF points is linked to the Scene Recognition System, to deliver superior subject detection and focus tracking performance. A single AF point can be selected from the 51 or 11 focus points. In Dynamic-area AF mode, you can select from either 9, 21 or 51 AF areas. The 51-point option offers 3D-Tracking mode, which automatically shifts the focus point to match the subject's movements. Auto-area AF mode gives greater priority to the subject's position when selecting AF points.
Choose from two Live View modes
Live View allows shooting while confirming the subject on the 3-inch, 920,000-dot color LCD monitor. In Handheld mode, which lets you recompose the frame prior to actual shooting, ordinary TTL phase-detection AF is activated, using all 51 AF points including 15 cross-type points. Tripod mode is designed for precise focus accuracy with still subjects and tripod stabilization. It enables focal-plane contrast-detect AF on a desired point within a specific area. Remote view, focusing and shooting can also be controlled from a PC (via connection or wireless) using optional Nikon Camera Control Pro 2 software.
DX cropping mode
The Nikon D700 lets you select from either FX format (36 x 24) or DX format (24 x 16). At the default setting of [Auto DX crop], the camera will automatically select DX format when a DX NIKKOR lens is attached.
High-definition, 3-inch VGA, TFT LCD monitor with wide viewing angle
The ultrahigh-definition [920,000-dot VGA (640 x 480)], 3-inch LCD monitor with tempered glass provides a 170° viewing angle. The large monitor is remarkably effective when confirming the focus with enlarged playback images. The wide viewing angle enables easy recomposing of the frame in Hand-held mode with Live View.
Viewfinder provides 95% frame coverage, 0.72x magnification in FX format
The viewfinder features an eye-level pentaprism with high refraction index and provides 95% frame coverage with 0.72x magnification. Fifty-one AF points and a framing grid are superimposed on the finder screen. The eyepoint is 18 mm (at –0.1 m-1), and the diopter can be adjusted within a range of –3 to +1 m-1.
Image Sensor Cleaning
Vibrations at four different resonant frequencies remove dust from the optical low-pass filter in front of the image sensor. This function is automatically activated each time the camera is turned on and off, and can also be activated on demand by the photographer.
Built-in flash with wireless commander function
With a guide number of approximately 17/56 (m/ft., ISO 200, 20°C/68°F) and 24mm lens coverage, the high-performance built-in flash enables i-TTL flash control that evaluates flash exposure with greater precision for exceptional results. Compatible with the Nikon Creative Lighting System, the built-in flash controls up to two groups of remote units as a master/commander in Advanced Wireless Lighting.
Engineered durability
A magnesium alloy is used for the exterior cover, rear body and mirror box to reduce weight and provide rugged durability. O-ring sealing where connections are made gives you valuable protection against dust and moisture. The shutter unit developed and manufactured by Nikon employs shutter blades made of a new material (a hybrid of carbon fiber and Kevlar). Tested on fully assembled cameras, the D700's shutter unit has been proven through 150,000 cycles under demanding conditions. The self-diagnostic shutter constantly monitors and maintains shutter precision.
Multi-Power Battery Pack MB-D10 (option)
The optional Multi-Power Battery Pack MB-D10, which uses one Rechargeable Li-ion Battery EN-EL4a/4/3e or eight AA-size batteries, is equipped with a shutter-release button, AF-ON button, multi selector, and main- and sub-command dials. When attached, it enables high-speed continuous shooting of 12.1-megapixel images at a rate of up to 8 fps*. * When using EN-EL4a/4 or eight AA-size batteries.
Exclusive Wireless Transmitter WT-4/4A (option)
The WT-4/4A supports both wired LAN (10BASE-T, 100BASE-TX) and wireless LAN (IEEE 802.11b/g, 11a), and incorporates a thumbnail mode. A PC allows wireless connection of up to five cameras, for display of thumbnail images and downloading of selected images. Using Camera Control Pro 2 (option) and the Live View function, wireless remote view/control shooting is also possible.
Fine tuning for AF
The focal point in AF for the current CPU lenses can be fine-tuned and registered. A certain level of adjustment set for up to 12 lens types is applied when a lens of the same type is attached. When using a lens that has not been registered, the same level of adjustment can be applied.
Improved Function button feature
In addition to the exclusive Function button, this feature can be assigned to the Preview button and the AE/AF Lock button, for optimum flexibility. Furthermore, NEF copy recording together with JPEG image can be assigned to the Function button.
HDMI output (High-Definition TV) supported
The D700 complies with HDMI (High-Definition Multimedia Interface) Ver. 1.3a for the transfer of global-standard video and audio signals. A Type C mini connector is provided.
Info display
Various shooting information is displayed on the LCD monitor, including shutter speed and aperture. Character color can be adjusted to match lighting conditions – black for light locations, white for dark locations. Auto switch mode can also be set.
My Menu
A variety of setting options can be customized under My Menu, then added to, deleted and reordered.
Electronic Virtual Horizon
Using a sensor incorporated in the body, the inclination of the camera is detected and displayed in the LCD monitor.
ViewNX/Nikon Transfer image-management software included in Software Suite CD-ROM
The ViewNX viewer application offers quick display of images; Nikon Transfer enables simple transfer of taken images to a computer.
Nikon Digital SLR Camera D700 Specifications
Type Single-lens reflex digital camera
Lens Mount Nikon F bayonet mount with AF coupling and AF contacts
Picture Angle Equivalent to angle produced by lens focal length
(1.5 times when DX format is selected)
Effective Pixels 12.1 million
Image Sensor CMOS sensor, 36.0 x 23.9 mm; Nikon FX format
Total Pixels 12.87 million
Dust-Reduction System Image sensor self-cleaning function, Image Dust Off reference data acquisition (Capture NX 2 required)
Image size (pixels) FX format (36 x 24): 4,256 x 2,832 [L], 3,184 x 2,120 [M], 2,128 x 1,416 [S]
DX format (24 x 16): 2,784 x 1,848 [L], 2,080 x 1,384 [M], 1,392 x 920 [S]
File Format • NEF (RAW): 12 or 14 bit, lossless compressed, compressed, or uncompressed
• TIFF (RGB)
• JPEG: JPEG-Baseline compliant with fine (approx. 1:4), normal (approx. 1:8), or basic (approx. 1:16) compression ([Size priority]); [Optimal quality] compression available
• NEF (RAW) + JPEG: Single photograph recorded in both NEF (RAW) and JPEG formats
Picture Control System
Four setting options: Standard, Neutral, Vivid, Monochrome; each option can be adjusted
Storage Media CompactFlash (Type I, compliant with UDMA)
File System Compliant with DCF 2.0, DPOF, Exif 2.21, Pictbridge
Viewfinder SLR-type with fixed eye-level pentaprism
Diopter Adjustment -3 to +1 m-1
Eyepoint 18 mm (-1.0 m-1)
Focusing Screen Type B BriteView Clear Matte VI screen with superimposed AF points and framing grid lines
Frame Coverage Approx. 95% (vertical/horizontal)
Magnification Approx. 0.72x (50mm f/1.4 lens at infinity; -1.0 m-1)
Reflex Mirror Quick-return type
Depth-of-field Preview When CPU lens is attached, lens aperture can be stopped down to value selected by user (A and M modes) or value selected by camera (P and S modes)
Lens Aperture Instant-return type, with depth-of-field preview button
Compatible Lenses • DX AF Nikkor: All functions supported
• Type G or D AF Nikkor: All functions supported (PC Micro-Nikkor does not support some functions). IX Nikkor lenses not supported.
• Other AF Nikkor: All functions supported except 3D Color Matrix Metering II. Lenses for F3AF not supported.
• AI-P Nikkor: All functions supported except autofocus and 3D Color Matrix Metering II
• Non-CPU AI Nikkor: Can be used in exposure modes A and M; electronic rangefinder can be used if maximum aperture is f/5.6 or faster; Color Matrix Metering and aperture value display supported if user provides lens data
Shutter Type Electronically controlled vertical-travel focal-plane shutter
Shutter Speed 1/8,000 to 30 s in steps of 1/3, 1/2 or 1 EV, Bulb, X250
Flash Sync Speed X = 1/250 s; synchronizes with shutter at 1/320 s or slower (flash range drops at speeds between 1/250 and 1/320 s)
Release Modes 1) Single-frame [S] mode
2) Continuous Low-speed [CL] mode
3) Continuous High-speed [CH] mode
4) Live View [LV] mode
5) Self-timer [mark] mode
6) Mirror-up [Mup] mode
Continuous Shooting Speed With Rechargeable Li-ion Battery EN-EL3e: 1-5 frames per second in [CL] mode, 5 fps in [CH] mode
With Multi-Power Battery Pack MB-D10 with batteries other than Rechargeable Li-ion Battery EN-EL3e or AC Adapter EH-5a/EH-5: 1-7 frames per second in [CL] mode, 8 fps in [CH] mode
Self-timer Electronically controlled timer with duration of 2, 5, 10 or 20 s
Metering TTL full-aperture exposure metering using 1,005-pixel RGB sensor
Metering System 1) 3D Color Matrix Metering II (type G and D lenses); Color Matrix Metering II (other CPU lenses); Color Matrix Metering (non-CPU lenses if user provides lens data)
2) Center-Weighted: Weight of 75% given to 8-, 12-, 15- or 20-mm circle in center of frame, or weighting based on average of entire frame
3) Spot: Meters 4-mm circle (about 1.5% of frame) centered on selected focus point (on center focus point when non-CPU lens is used)
Metering Range 1) 0 to 20 EV (Matrix or Center-Weighted Metering)
2) 2 to 20 EV (Spot Metering) (ISO 100 equivalent, f/1.4 lens, at 20°C/68°F)
Exposure Meter Coupling Combined CPU and AI
Exposure Modes 1) Programmed Auto (P) with flexible program
2) Shutter-Priority Auto (S)
3) Aperture-Priority Auto (A)
4) Manual (M)
Exposure Compensation ±5 EV in increments of 1/3, 1/2 or 1 EV
Exposure Lock Exposure locked at detected value with AE-L/AF-L button
Exposure Bracketing Exposure and/or flash bracketing (2 to 9 exposures in increments of 1/3, 1/2, 2/3 or 1 EV)
Sensitivity ISO 200 to 6400 in steps of 1/3, 1/2, or 1 EV; can be set to approx. 0.3, 0.5, 0.7, or 1 (ISO 100 equivalent) EV below ISO 200, or to approx. 0.3, 0.5, 0.7, 1 (ISO 12800 equivalent), or 2 (ISO 25600 equivalent) EV over ISO 6400
Active D-Lighting Can be selected from [Auto], [High], [Normal], or [Low]
Autofocus TTL phase-detection AF, 51 focus points (15 cross-sensors) by Nikon Multi-CAM 3500FX autofocus module; Detection: -1 to +19 EV (ISO 100 at 20°C/68°F); AF fine tuning possible; AF-assist illuminator (range approx. 0.5-3 m/1.6-9.8 ft.)
Lens Servo 1) Autofocus: Single-servo AF (S); Continuous-servo AF (C); Focus Tracking automatically activated according to subject status
2) Manual focus (M) with electronic rangefinder
Focus Point Single AF point can be selected from 51 or 11 focus points
AF-Area Mode 1) Single-point AF
2) Dynamic-area AF [number of AF points: 9, 21, 51, 51 (3D-Tracking)]
3) Auto-area AF
Built-in Flash Manual pop-up type; guide number of 17/56 (ISO 200, m/ft., 20°C/68°F) or 12/39 (ISO 100, m/ft., 20°C/68°F)
Flash Control 1) TTL flash control with 1,005-pixel RGB sensor; i-TTL balanced fill-flash and standard i-TTL fill-flash available with SB-900, 800, 600 or 400
2) Auto aperture (AA): Available with SB-900, 800 and CPU lens
3) Non-TTL auto (A): Available with SB-900, 800, 28, 27 or 22s
4) Distance-priority manual (GN): Available with SB-900, 800
Flash Sync Modes 1) Front-curtain sync (normal)
2) Slow sync
3) Rear-curtain sync
4) Red-eye reduction
5) Red-eye reduction with slow sync
Flash Compensation -3 to +1 EV in increments of 1/3, 1/2 or 1 EV
Flash-ready Indicator Lights when Speedlight such as SB-900, SB-800, SB-600, SB-400, SB-80DX, SB-28DX, or SB-50DX is fully charged; blinks after flash is fired at full output
Accessory Shoe Standard ISO 518 hot-shoe contact with safety lock
Sync Terminal ISO 519 standard terminal
Nikon Creative Lighting System With Speedlights such as SB-900, SB-800, SB-600, SB-R200, or SU-800 (commander only), supports Advanced Wireless Lighting, Auto FP High-Speed Sync, Flash Color Information Communication, modeling flash and FV lock; built-in flash can be used as a commander
White Balance • Auto (TTL white balance with main image sensor and 1,005-pixel RGB sensor);
• Seven manual modes can be preset with fine-tuning; color temperature setting; white balance bracketing: 2 to 9 exposures in increments of 1, 2 or 3
Live View Modes Hand-held mode: TTL phase-detection AF with 51 focus areas (15 cross-type sensors) Tripod mode: Contrast-detect AF on a desired point within a specific area
LCD Monitor 3-in., approx. 920,000-dot (VGA), 170-degree wide-viewing-angle, 100% frame coverage, low-temperature polysilicon TFT LCD with brightness adjustment
Playback Function Full-frame and thumbnail (4 or 9 images) playback with playback zoom, slide show, histogram display, highlight display, auto image rotation, and image comment (up to 36 characters)
USB Hi-Speed USB
Video Output NTSC or PAL; simultaneous playback from both the video output and on the LCD monitor available
HDMI Output Supports HDMI version 1.3a; Type C mini connector is provided; simultaneous playback from both the HDMI output terminal and on the LCD monitor not available
Ten-pin Terminal 1) GPS: NMEA 0183 (Ver. 2.01 and 3.01) interface standard supported with 9-pin D-sub cable and GPS Cable MC-35 (optional)
2) Remote control: via Ten-pin terminal
Supported Languages Chinese (Simplified and Traditional), Dutch, English, Finnish, French, German, Italian, Japanese, Korean, Polish, Portuguese, Russian, Spanish, Swedish
Battery One Rechargeable Li-ion Battery EN-EL3e
Battery Pack Multi-Power Battery Pack MB-D10 (optional) with one Rechargeable Li-ion Battery EN-EL4a/EN-EL4 (battery chamber cover BL-3 required) or EN-EL3e, or eight R6/AA-size alkaline (LR6), Ni-MH (HR6), lithium (FR6) batteries, or nickel-manganese (ZR6) batteries
AC Adapter AC Adapter EH-5a/EH-5 (optional)
Tripod Socket 1/4 in. (ISO 1222)
Dimensions (W x H x D) Approx. 147 x 123 x 77 mm/5.8 x 4.8 x 3.0 in.
Weight Approx. 995 g/2.19 lb. without battery, memory card, body cap or LCD monitor cover
Temperature 0-40°C/32-104°F
Humidity Under 85% (no condensation)
Supplied Accessories* Rechargeable Li-ion Battery EN-EL3e, Quick Charger MH-18a, USB Cable UC-E4, Video Cable EG-D100, Camera Strap AN-D700, Body Cap BF-1A, Accessory Shoe Cover BS-1, LCD Monitor Cover BM-9, Software Suite CD-ROM
*Supplied accessories may differ depending on country or area
Main Optional Accessories Wireless Transmitter WT-4/4A, Magnifying Eyepiece DK-17M, AC Adapter EH-5a, Capture NX 2 Software, Camera Control Pro 2 Software, Image Authentication Software
July 1, 2008
Nikon FX-format digital SLR – exceptional performance combined with superior mobility and functional versatility to provide serious photographers with outstanding value
D700
TOKYO – Nikon Corporation is pleased to announce the introduction of its newest FX-format digital SLR, the Nikon D700.
The D700 features an FX-format first introduced with the Nikon D3. Highly praised for its outstanding features, the D3 established a new level of professional performance in terms of overall image quality, extraordinarily low noise, ISO sensitivity range, continuous high-speed shooting, color gradation, image crispness, durability, weather-resistant operation, system versatility and more.
The new D700 incorporates an extensive array of features that boast a level of performance that is in many ways comparable to the D3. At the same time, it derives a wide range of benefits – including functionality, flexibility and operability – from the more agile D300, Nikon's flagship DX-format D-SLR.
The D700 has everything it takes to satisfy a broad spectrum of photographic needs. The 12.1-megapixel FX-format CMOS sensor with a sensing area of 36.0 x 23.9 mm; a sensitivity range of ISO 200 to 6400; continuous shooting at up to 5 frames per second (and up to 8 fps with the optional Multi-Power Battery Pack MB-D10; Nikon's exclusive 51-point AF system; Scene Recognition System for optimum autofocus, auto exposure and auto white balance detection – these are but a few of the advanced capabilities of the extraordinary new D700.
Major Features
Large image sensor, developed by Nikon; 12.1 effective megapixels
The D700 employs an FX-format CMOS image sensor with an area of 36.0mm (h) x 23.9mm (v). It provides superior picture quality throughout a wide ISO sensitivity range, with advantages that include a large pixel size to ensure a higher signal-to-noise ratio and wide dynamic range, and improved circuit layout to efficiently increase the strength of the electrical signal from pixels. High-speed, 12-channel readout enables fast continuous shooting of high-resolution images at up to 8 frames per second (with Multi-Power Battery Pack MB-D10 and Rechargeable Li-ion Battery EN-EL4a/4 or eight AA-size batteries).
Wide sensitivity range
The D700 offers an extremely wide sensitivity range of ISO 200 to 6400. It delivers extraordinary image quality at low sensitivity settings, while also delivering outstandingly low-noise characteristics at ISO settings as high as 6400. Furthermore, sensitivity can be increased to HI 0.3, HI 0.5, HI 0.7, HI 1 (ISO 12,800 equivalent), HI 2 (ISO 25,600 equivalent), or decreased to Lo 1 (ISO 100 equivalent), Lo 0.7, Lo 0.5 and Lo 0.3, to expand shooting versatility.
High-speed performance
Features a startup time of approximately 0.12 second, and a shutter release time lag of only 40 ms* – both equivalent to the flagship Nikon D3. The continuous shooting speed is up to 5 frames per second with the included Rechargeable Li-ion Battery EN-EL3e, and up to 8 fps when using the optional Multi-Power Battery Pack MB-D10 and Rechargeable Li-ion Battery EN-EL4a/4 or eight AA-size batteries. The Nikon D700 is also compliant with the next-generation high-speed UDMA CompactFlash cards, that will enable 35-Mbyte recording speed.
* Based on the new CIPA guideline established in August 2007.
EXPEED image processing
Nikon's state-of-the-art EXPEED digital image-processing incorporates remarkable intelligence and technologies accumulated and optimized throughout our long history. It makes possible a diverse range of functions that ensure superior picture quality and high-speed image processing.
Scene Recognition System
Improvements to the exclusive 1,005-pixel RGB light sensor have allowed information from the sensor to be utilized for auto exposure, auto white balance and autofocus. 3D-Tracking in AF, for example, achieved by using the Scene Recognition System, tracks subject position and automatically shifts the AF points used to match the subject's movement within the frame. This system also contributes to higher accuracy of auto exposure and auto white balance detection.
Picture Control System
Nikon's Control System enables users, from novices to professionals, to create the pictures they envision by making specific selections and adjustments to image sharpening, tone compensation, brightness, tone and saturation. Even with different cameras, when the settings are the same, you get the same picture tone. Picture Control System offers four fundamental setting options – Standard, Neutral, Vivid and Monochrome – for easy customization of image parameters.
Active D-Lighting
Active D-Lighting lets photographers choose from various intensities – Auto, High, Normal, Low or OFF (Unchanged) – prior to shooting. Instead of employing the conventional compensation method of simply expanding dynamic range, localized tone control technology is utilized to ensure proper contrast and eliminate flat images with lost highlights and shadows.
AF system with high-density 51-point AF
The D700 incorporates a Multi-CAM 3500FX autofocus sensor module featuring 51 AF points. Fifteen cross-type sensors located in the center enable subject detection with lens apertures as small as f/5.6. The functioning of the AF points is linked to the Scene Recognition System, to deliver superior subject detection and focus tracking performance. A single AF point can be selected from the 51 or 11 focus points. In Dynamic-area AF mode, you can select from either 9, 21 or 51 AF areas. The 51-point option offers 3D-Tracking mode, which automatically shifts the focus point to match the subject's movements. Auto-area AF mode gives greater priority to the subject's position when selecting AF points.
Choose from two Live View modes
Live View allows shooting while confirming the subject on the 3-inch, 920,000-dot color LCD monitor. In Handheld mode, which lets you recompose the frame prior to actual shooting, ordinary TTL phase-detection AF is activated, using all 51 AF points including 15 cross-type points. Tripod mode is designed for precise focus accuracy with still subjects and tripod stabilization. It enables focal-plane contrast-detect AF on a desired point within a specific area. Remote view, focusing and shooting can also be controlled from a PC (via connection or wireless) using optional Nikon Camera Control Pro 2 software.
DX cropping mode
The Nikon D700 lets you select from either FX format (36 x 24) or DX format (24 x 16). At the default setting of [Auto DX crop], the camera will automatically select DX format when a DX NIKKOR lens is attached.
High-definition, 3-inch VGA, TFT LCD monitor with wide viewing angle
The ultrahigh-definition [920,000-dot VGA (640 x 480)], 3-inch LCD monitor with tempered glass provides a 170° viewing angle. The large monitor is remarkably effective when confirming the focus with enlarged playback images. The wide viewing angle enables easy recomposing of the frame in Hand-held mode with Live View.
Viewfinder provides 95% frame coverage, 0.72x magnification in FX format
The viewfinder features an eye-level pentaprism with high refraction index and provides 95% frame coverage with 0.72x magnification. Fifty-one AF points and a framing grid are superimposed on the finder screen. The eyepoint is 18 mm (at –0.1 m-1), and the diopter can be adjusted within a range of –3 to +1 m-1.
Image Sensor Cleaning
Vibrations at four different resonant frequencies remove dust from the optical low-pass filter in front of the image sensor. This function is automatically activated each time the camera is turned on and off, and can also be activated on demand by the photographer.
Built-in flash with wireless commander function
With a guide number of approximately 17/56 (m/ft., ISO 200, 20°C/68°F) and 24mm lens coverage, the high-performance built-in flash enables i-TTL flash control that evaluates flash exposure with greater precision for exceptional results. Compatible with the Nikon Creative Lighting System, the built-in flash controls up to two groups of remote units as a master/commander in Advanced Wireless Lighting.
Engineered durability
A magnesium alloy is used for the exterior cover, rear body and mirror box to reduce weight and provide rugged durability. O-ring sealing where connections are made gives you valuable protection against dust and moisture. The shutter unit developed and manufactured by Nikon employs shutter blades made of a new material (a hybrid of carbon fiber and Kevlar). Tested on fully assembled cameras, the D700's shutter unit has been proven through 150,000 cycles under demanding conditions. The self-diagnostic shutter constantly monitors and maintains shutter precision.
Multi-Power Battery Pack MB-D10 (option)
The optional Multi-Power Battery Pack MB-D10, which uses one Rechargeable Li-ion Battery EN-EL4a/4/3e or eight AA-size batteries, is equipped with a shutter-release button, AF-ON button, multi selector, and main- and sub-command dials. When attached, it enables high-speed continuous shooting of 12.1-megapixel images at a rate of up to 8 fps*. * When using EN-EL4a/4 or eight AA-size batteries.
Exclusive Wireless Transmitter WT-4/4A (option)
The WT-4/4A supports both wired LAN (10BASE-T, 100BASE-TX) and wireless LAN (IEEE 802.11b/g, 11a), and incorporates a thumbnail mode. A PC allows wireless connection of up to five cameras, for display of thumbnail images and downloading of selected images. Using Camera Control Pro 2 (option) and the Live View function, wireless remote view/control shooting is also possible.
Fine tuning for AF
The focal point in AF for the current CPU lenses can be fine-tuned and registered. A certain level of adjustment set for up to 12 lens types is applied when a lens of the same type is attached. When using a lens that has not been registered, the same level of adjustment can be applied.
Improved Function button feature
In addition to the exclusive Function button, this feature can be assigned to the Preview button and the AE/AF Lock button, for optimum flexibility. Furthermore, NEF copy recording together with JPEG image can be assigned to the Function button.
HDMI output (High-Definition TV) supported
The D700 complies with HDMI (High-Definition Multimedia Interface) Ver. 1.3a for the transfer of global-standard video and audio signals. A Type C mini connector is provided.
Info display
Various shooting information is displayed on the LCD monitor, including shutter speed and aperture. Character color can be adjusted to match lighting conditions – black for light locations, white for dark locations. Auto switch mode can also be set.
My Menu
A variety of setting options can be customized under My Menu, then added to, deleted and reordered.
Electronic Virtual Horizon
Using a sensor incorporated in the body, the inclination of the camera is detected and displayed in the LCD monitor.
ViewNX/Nikon Transfer image-management software included in Software Suite CD-ROM
The ViewNX viewer application offers quick display of images; Nikon Transfer enables simple transfer of taken images to a computer.
Nikon Digital SLR Camera D700 Specifications
Type Single-lens reflex digital camera
Lens Mount Nikon F bayonet mount with AF coupling and AF contacts
Picture Angle Equivalent to angle produced by lens focal length
(1.5 times when DX format is selected)
Effective Pixels 12.1 million
Image Sensor CMOS sensor, 36.0 x 23.9 mm; Nikon FX format
Total Pixels 12.87 million
Dust-Reduction System Image sensor self-cleaning function, Image Dust Off reference data acquisition (Capture NX 2 required)
Image size (pixels) FX format (36 x 24): 4,256 x 2,832 [L], 3,184 x 2,120 [M], 2,128 x 1,416 [S]
DX format (24 x 16): 2,784 x 1,848 [L], 2,080 x 1,384 [M], 1,392 x 920 [S]
File Format • NEF (RAW): 12 or 14 bit, lossless compressed, compressed, or uncompressed
• TIFF (RGB)
• JPEG: JPEG-Baseline compliant with fine (approx. 1:4), normal (approx. 1:8), or basic (approx. 1:16) compression ([Size priority]); [Optimal quality] compression available
• NEF (RAW) + JPEG: Single photograph recorded in both NEF (RAW) and JPEG formats
Picture Control System
Four setting options: Standard, Neutral, Vivid, Monochrome; each option can be adjusted
Storage Media CompactFlash (Type I, compliant with UDMA)
File System Compliant with DCF 2.0, DPOF, Exif 2.21, Pictbridge
Viewfinder SLR-type with fixed eye-level pentaprism
Diopter Adjustment -3 to +1 m-1
Eyepoint 18 mm (-1.0 m-1)
Focusing Screen Type B BriteView Clear Matte VI screen with superimposed AF points and framing grid lines
Frame Coverage Approx. 95% (vertical/horizontal)
Magnification Approx. 0.72x (50mm f/1.4 lens at infinity; -1.0 m-1)
Reflex Mirror Quick-return type
Depth-of-field Preview When CPU lens is attached, lens aperture can be stopped down to value selected by user (A and M modes) or value selected by camera (P and S modes)
Lens Aperture Instant-return type, with depth-of-field preview button
Compatible Lenses • DX AF Nikkor: All functions supported
• Type G or D AF Nikkor: All functions supported (PC Micro-Nikkor does not support some functions). IX Nikkor lenses not supported.
• Other AF Nikkor: All functions supported except 3D Color Matrix Metering II. Lenses for F3AF not supported.
• AI-P Nikkor: All functions supported except autofocus and 3D Color Matrix Metering II
• Non-CPU AI Nikkor: Can be used in exposure modes A and M; electronic rangefinder can be used if maximum aperture is f/5.6 or faster; Color Matrix Metering and aperture value display supported if user provides lens data
Shutter Type Electronically controlled vertical-travel focal-plane shutter
Shutter Speed 1/8,000 to 30 s in steps of 1/3, 1/2 or 1 EV, Bulb, X250
Flash Sync Speed X = 1/250 s; synchronizes with shutter at 1/320 s or slower (flash range drops at speeds between 1/250 and 1/320 s)
Release Modes 1) Single-frame [S] mode
2) Continuous Low-speed [CL] mode
3) Continuous High-speed [CH] mode
4) Live View [LV] mode
5) Self-timer [mark] mode
6) Mirror-up [Mup] mode
Continuous Shooting Speed With Rechargeable Li-ion Battery EN-EL3e: 1-5 frames per second in [CL] mode, 5 fps in [CH] mode
With Multi-Power Battery Pack MB-D10 with batteries other than Rechargeable Li-ion Battery EN-EL3e or AC Adapter EH-5a/EH-5: 1-7 frames per second in [CL] mode, 8 fps in [CH] mode
Self-timer Electronically controlled timer with duration of 2, 5, 10 or 20 s
Metering TTL full-aperture exposure metering using 1,005-pixel RGB sensor
Metering System 1) 3D Color Matrix Metering II (type G and D lenses); Color Matrix Metering II (other CPU lenses); Color Matrix Metering (non-CPU lenses if user provides lens data)
2) Center-Weighted: Weight of 75% given to 8-, 12-, 15- or 20-mm circle in center of frame, or weighting based on average of entire frame
3) Spot: Meters 4-mm circle (about 1.5% of frame) centered on selected focus point (on center focus point when non-CPU lens is used)
Metering Range 1) 0 to 20 EV (Matrix or Center-Weighted Metering)
2) 2 to 20 EV (Spot Metering) (ISO 100 equivalent, f/1.4 lens, at 20°C/68°F)
Exposure Meter Coupling Combined CPU and AI
Exposure Modes 1) Programmed Auto (P) with flexible program
2) Shutter-Priority Auto (S)
3) Aperture-Priority Auto (A)
4) Manual (M)
Exposure Compensation ±5 EV in increments of 1/3, 1/2 or 1 EV
Exposure Lock Exposure locked at detected value with AE-L/AF-L button
Exposure Bracketing Exposure and/or flash bracketing (2 to 9 exposures in increments of 1/3, 1/2, 2/3 or 1 EV)
Sensitivity ISO 200 to 6400 in steps of 1/3, 1/2, or 1 EV; can be set to approx. 0.3, 0.5, 0.7, or 1 (ISO 100 equivalent) EV below ISO 200, or to approx. 0.3, 0.5, 0.7, 1 (ISO 12800 equivalent), or 2 (ISO 25600 equivalent) EV over ISO 6400
Active D-Lighting Can be selected from [Auto], [High], [Normal], or [Low]
Autofocus TTL phase-detection AF, 51 focus points (15 cross-sensors) by Nikon Multi-CAM 3500FX autofocus module; Detection: -1 to +19 EV (ISO 100 at 20°C/68°F); AF fine tuning possible; AF-assist illuminator (range approx. 0.5-3 m/1.6-9.8 ft.)
Lens Servo 1) Autofocus: Single-servo AF (S); Continuous-servo AF (C); Focus Tracking automatically activated according to subject status
2) Manual focus (M) with electronic rangefinder
Focus Point Single AF point can be selected from 51 or 11 focus points
AF-Area Mode 1) Single-point AF
2) Dynamic-area AF [number of AF points: 9, 21, 51, 51 (3D-Tracking)]
3) Auto-area AF
Built-in Flash Manual pop-up type; guide number of 17/56 (ISO 200, m/ft., 20°C/68°F) or 12/39 (ISO 100, m/ft., 20°C/68°F)
Flash Control 1) TTL flash control with 1,005-pixel RGB sensor; i-TTL balanced fill-flash and standard i-TTL fill-flash available with SB-900, 800, 600 or 400
2) Auto aperture (AA): Available with SB-900, 800 and CPU lens
3) Non-TTL auto (A): Available with SB-900, 800, 28, 27 or 22s
4) Distance-priority manual (GN): Available with SB-900, 800
Flash Sync Modes 1) Front-curtain sync (normal)
2) Slow sync
3) Rear-curtain sync
4) Red-eye reduction
5) Red-eye reduction with slow sync
Flash Compensation -3 to +1 EV in increments of 1/3, 1/2 or 1 EV
Flash-ready Indicator Lights when Speedlight such as SB-900, SB-800, SB-600, SB-400, SB-80DX, SB-28DX, or SB-50DX is fully charged; blinks after flash is fired at full output
Accessory Shoe Standard ISO 518 hot-shoe contact with safety lock
Sync Terminal ISO 519 standard terminal
Nikon Creative Lighting System With Speedlights such as SB-900, SB-800, SB-600, SB-R200, or SU-800 (commander only), supports Advanced Wireless Lighting, Auto FP High-Speed Sync, Flash Color Information Communication, modeling flash and FV lock; built-in flash can be used as a commander
White Balance • Auto (TTL white balance with main image sensor and 1,005-pixel RGB sensor);
• Seven manual modes can be preset with fine-tuning; color temperature setting; white balance bracketing: 2 to 9 exposures in increments of 1, 2 or 3
Live View Modes Hand-held mode: TTL phase-detection AF with 51 focus areas (15 cross-type sensors) Tripod mode: Contrast-detect AF on a desired point within a specific area
LCD Monitor 3-in., approx. 920,000-dot (VGA), 170-degree wide-viewing-angle, 100% frame coverage, low-temperature polysilicon TFT LCD with brightness adjustment
Playback Function Full-frame and thumbnail (4 or 9 images) playback with playback zoom, slide show, histogram display, highlight display, auto image rotation, and image comment (up to 36 characters)
USB Hi-Speed USB
Video Output NTSC or PAL; simultaneous playback from both the video output and on the LCD monitor available
HDMI Output Supports HDMI version 1.3a; Type C mini connector is provided; simultaneous playback from both the HDMI output terminal and on the LCD monitor not available
Ten-pin Terminal 1) GPS: NMEA 0183 (Ver. 2.01 and 3.01) interface standard supported with 9-pin D-sub cable and GPS Cable MC-35 (optional)
2) Remote control: via Ten-pin terminal
Supported Languages Chinese (Simplified and Traditional), Dutch, English, Finnish, French, German, Italian, Japanese, Korean, Polish, Portuguese, Russian, Spanish, Swedish
Battery One Rechargeable Li-ion Battery EN-EL3e
Battery Pack Multi-Power Battery Pack MB-D10 (optional) with one Rechargeable Li-ion Battery EN-EL4a/EN-EL4 (battery chamber cover BL-3 required) or EN-EL3e, or eight R6/AA-size alkaline (LR6), Ni-MH (HR6), lithium (FR6) batteries, or nickel-manganese (ZR6) batteries
AC Adapter AC Adapter EH-5a/EH-5 (optional)
Tripod Socket 1/4 in. (ISO 1222)
Dimensions (W x H x D) Approx. 147 x 123 x 77 mm/5.8 x 4.8 x 3.0 in.
Weight Approx. 995 g/2.19 lb. without battery, memory card, body cap or LCD monitor cover
Temperature 0-40°C/32-104°F
Humidity Under 85% (no condensation)
Supplied Accessories* Rechargeable Li-ion Battery EN-EL3e, Quick Charger MH-18a, USB Cable UC-E4, Video Cable EG-D100, Camera Strap AN-D700, Body Cap BF-1A, Accessory Shoe Cover BS-1, LCD Monitor Cover BM-9, Software Suite CD-ROM
*Supplied accessories may differ depending on country or area
Main Optional Accessories Wireless Transmitter WT-4/4A, Magnifying Eyepiece DK-17M, AC Adapter EH-5a, Capture NX 2 Software, Camera Control Pro 2 Software, Image Authentication Software
Saturday, June 28, 2008
Friday, June 27, 2008
Wednesday, June 25, 2008
Sunday, June 22, 2008
Photo Exposure
Photo Exposure: In photography, exposure is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance.
Correct exposure
The "correct" exposure for a photograph is determined by the sensitivity of the medium used. For photographic film, sensitivity is referred to as film speed and is measured on a scale published by the International Organization for Standardization (ISO). Faster film requires less exposure and has a higher ISO rating. Exposure is a combination of the length of time and the level of illumination received by the photosensitive material. Exposure time is controlled in a camera by shutter speed and the illumination level by the lens aperture. Slower shutter speeds (exposing the medium for a longer period of time) and greater lens apertures (admitting more light) produce greater exposures.
An approximately correct exposure will be obtained on a sunny day using ISO 100 film, an aperture of f/16 and a shutter speed of 1/100th of a second. This is called the sunny 16 rule: at an aperture of f/16 on a sunny day, a suitable shutter speed will be one over the film speed (or closest equivalent).
Ultimately there is no such thing as "correct exposure", as a scene can be exposed in many ways, depending on the desired effect a photographer wishes to convey.
Exposure is controlled by 5 factors:
1. Aperture
2. Shutter Speed
3. Film/ISO Speed
4. Focal length of the lens
5. Metering - how your camera measures light
Photograph: This is the end result of your photo exposure. With slides, it's the picture you see in the slide viewer or projected on a screen. This is as near to how you saw the image through the camera as you'll get and is really only affected by the film brand you use (Kodak, Fuji, Agfa, etc.) as each will respond in slightly different ways to light.
if you use negative/print film, it's one step removed from your photo exposure since the lab that produces the final print uses machines that are set by human operators, at least to some degree and there's a certain amount of subjective assessment in getting the color balance right in the final photo. How many times have your photos come back from the lab with a color cast? Or looking flat, lacking vibrancy? A lot of that's down to a bad lab rather than a bad photo exposure.
If you use a digital camera, then your photograph will appear on your monitor or TV Screen. How it appears will depend on the brightness, contrast and color settings of your screen. In addition, your camera may do some in-camera processing on your image such as sharpening, adjusting the brightness and contrast and maybe trying to balance the colors before the image is finally stored on your memory card.
A Digital SLR provides an option for storing images in what's called RAW mode. This means the camera does absolutely no processing of the image before writing it to the memory card. It's then up to you to import the image into an image processing package like Adobe PhotoShop, PhotoShop Elements or Paint Shop Pro so you can manipulate the image exactly as you want.
Whatever digital image you do take, whether in RAW mode or as a preprocessed JPG, may need some tweaking before you're completely happy with it. This is where digital supercedes film. Using the image manipulation packages mentioned above, your PC becomes an electronic darkroom and gives you much more control over the final image. You'd need a darkroom, enlarger and chemicals to do that with film-based photos. You could of course invest in a film scanner to convert your film images into digital scans. But it's one more expense.
If you want to print out your digital image, you need a color inkjet printer. To get the best results, you need to calibrate it with your monitor so the colors you see on it (and are happy with) are the one that get printed out. Alternatively, you can hand your digital images over to a color lab and have them print them out for you. Prices these days are very reasonable.
That final image, the one you're happy with is the photograph. It may be very close to the photo exposure you originally made or it may differ substantially because you tweaked brightness, contrast or color or the lab did a lousy job of printing from your negatives.
The photograph is the end result.
Aperture & Shutter Speed
Aperture and shutter speed work together. Aperture is measured in f-stops and shutter speed in seconds or fractions of a second. Because both are calibrated so that each setting changes by a factor of two (newer digital SLRs break that rule) they are, to some extent, interchangeable in controlling the amount of light that makes up the photo exposure.
The amount of light entering the camera with a photo exposure setting of f/5.6 at 1/250 sec is the same as f/8 at 1/125 sec; i.e. half the shutter speed and double the aperture. Make changes in one setting and alter the other correspondingly and, all things being equal, the photo exposure will be the same.
Shutter speed and aperture have quite different pictorial effects. Aperture affects the depth of field - how much of what you see in the viewfinder will be in focus; shutter speed determines whether movement is blurred (slow shutter speed) or frozen (fast shutter speed).
Which one you give priority to depends on how you see your subject and what you want to capture in your photo. SLR cameras frequently provide program modes that prioritise aperture or shutter speed; e.g. in aperture priority mode, you set the aperture to a value for the photo you want to take and the camera adjusts the shutter speed accordingly.
ISO Speed
Film/ISO speed determines how fast the film or CCD sensor reacts to light. The slower the speed, the slower the reaction to light so longer shutter speeds are required which, in turn, will affect the apertures you can use.
The ISO speed is fixed for film-based cameras. Those silver squares you see on the film casing tell the camera what the film's ISO speed is.
On digital cameras, the ISO speed determines how fast the sensor responds to light. This setting can be changed to any ISO setting the camera provides, so you have much more freedom in the pictures you can take. You could take one photo exposure at ISO 50 in good daylight conditions, the next one might be at ISO 1600 to bring out detail at night and so on.
Both film and CCD sesors suffer from grain. Both have fine granularity at low ISO settings and both have noticable grain at high ISO settings. So there is a trade-off between the amount of grain you want in your final image and the ISO speed that's called for in any given situation.
Focal Length
Lenses come in different focal lengths ranging from 16mm fisheye lenses through 28mm and 35mm wide angle lenses to the standard 50mm, and 135mm and 500mm telephoto lenses. And then you have the zoom lenses that traverse various focal lengths such as 28-80mm, 75-210mm and so on. Adorama have a huge selection of lenses and accessories, so you should find something there to suit your camera.
The actual definition of focal length is a bit technical. It's defined as the distance in mm from the optical center of the lens to the focal point, which is located on the sensor or film if the image is "in focus". The camera lens projects part of the scene onto the film or sensor. The field of view (FOV) is determined by the angle of view from the lens out to the scene and can be measured horizontally or vertically. Larger sensors or films have wider FOVs and can capture more of the scene. In other words, the longer the focal length, the closer objects appear through it and the smaller the area of the scene you can see (because you're zooming in on a smaller part of it).
Focal length affects the depth of field in your pictures which in turn affects the shutter speeds you can use, all of which are governed by the ISO speed you're using.
Metering
Your photo exposure is the key to successful landscape shots. You'll find a guide to the main metering options offered by SLR and creative compact cameras here.
One thing to beware of is burned out skies or dull featureless foregrounds. These occur when there's a large difference in brightness between the sky and the foreground. In such cases, you're better off using a graduated-filter to bring the brightess difference within the range that the film or digital sensor can record. Your first step is to determine the strength of filter you'll need. The simplest method is to take a meter reading with the ground filling the whole of the frame without the filter in place. Now repeat this step but this time with the sky filling the frame. The difference between these two readings will indicate the strength of graduated filter that you need. A 1-stop difference in the readings will need a 0.3 ND graduated filter, a 2-stop difference a 0.6 ND grad, while a 3-stop difference will require a 0.9 ND grad.
visit www.leenn.com
Correct exposure
The "correct" exposure for a photograph is determined by the sensitivity of the medium used. For photographic film, sensitivity is referred to as film speed and is measured on a scale published by the International Organization for Standardization (ISO). Faster film requires less exposure and has a higher ISO rating. Exposure is a combination of the length of time and the level of illumination received by the photosensitive material. Exposure time is controlled in a camera by shutter speed and the illumination level by the lens aperture. Slower shutter speeds (exposing the medium for a longer period of time) and greater lens apertures (admitting more light) produce greater exposures.
An approximately correct exposure will be obtained on a sunny day using ISO 100 film, an aperture of f/16 and a shutter speed of 1/100th of a second. This is called the sunny 16 rule: at an aperture of f/16 on a sunny day, a suitable shutter speed will be one over the film speed (or closest equivalent).
Ultimately there is no such thing as "correct exposure", as a scene can be exposed in many ways, depending on the desired effect a photographer wishes to convey.
Exposure is controlled by 5 factors:
1. Aperture
2. Shutter Speed
3. Film/ISO Speed
4. Focal length of the lens
5. Metering - how your camera measures light
Photograph: This is the end result of your photo exposure. With slides, it's the picture you see in the slide viewer or projected on a screen. This is as near to how you saw the image through the camera as you'll get and is really only affected by the film brand you use (Kodak, Fuji, Agfa, etc.) as each will respond in slightly different ways to light.
if you use negative/print film, it's one step removed from your photo exposure since the lab that produces the final print uses machines that are set by human operators, at least to some degree and there's a certain amount of subjective assessment in getting the color balance right in the final photo. How many times have your photos come back from the lab with a color cast? Or looking flat, lacking vibrancy? A lot of that's down to a bad lab rather than a bad photo exposure.
If you use a digital camera, then your photograph will appear on your monitor or TV Screen. How it appears will depend on the brightness, contrast and color settings of your screen. In addition, your camera may do some in-camera processing on your image such as sharpening, adjusting the brightness and contrast and maybe trying to balance the colors before the image is finally stored on your memory card.
A Digital SLR provides an option for storing images in what's called RAW mode. This means the camera does absolutely no processing of the image before writing it to the memory card. It's then up to you to import the image into an image processing package like Adobe PhotoShop, PhotoShop Elements or Paint Shop Pro so you can manipulate the image exactly as you want.
Whatever digital image you do take, whether in RAW mode or as a preprocessed JPG, may need some tweaking before you're completely happy with it. This is where digital supercedes film. Using the image manipulation packages mentioned above, your PC becomes an electronic darkroom and gives you much more control over the final image. You'd need a darkroom, enlarger and chemicals to do that with film-based photos. You could of course invest in a film scanner to convert your film images into digital scans. But it's one more expense.
If you want to print out your digital image, you need a color inkjet printer. To get the best results, you need to calibrate it with your monitor so the colors you see on it (and are happy with) are the one that get printed out. Alternatively, you can hand your digital images over to a color lab and have them print them out for you. Prices these days are very reasonable.
That final image, the one you're happy with is the photograph. It may be very close to the photo exposure you originally made or it may differ substantially because you tweaked brightness, contrast or color or the lab did a lousy job of printing from your negatives.
The photograph is the end result.
Aperture & Shutter Speed
Aperture and shutter speed work together. Aperture is measured in f-stops and shutter speed in seconds or fractions of a second. Because both are calibrated so that each setting changes by a factor of two (newer digital SLRs break that rule) they are, to some extent, interchangeable in controlling the amount of light that makes up the photo exposure.
The amount of light entering the camera with a photo exposure setting of f/5.6 at 1/250 sec is the same as f/8 at 1/125 sec; i.e. half the shutter speed and double the aperture. Make changes in one setting and alter the other correspondingly and, all things being equal, the photo exposure will be the same.
Shutter speed and aperture have quite different pictorial effects. Aperture affects the depth of field - how much of what you see in the viewfinder will be in focus; shutter speed determines whether movement is blurred (slow shutter speed) or frozen (fast shutter speed).
Which one you give priority to depends on how you see your subject and what you want to capture in your photo. SLR cameras frequently provide program modes that prioritise aperture or shutter speed; e.g. in aperture priority mode, you set the aperture to a value for the photo you want to take and the camera adjusts the shutter speed accordingly.
ISO Speed
Film/ISO speed determines how fast the film or CCD sensor reacts to light. The slower the speed, the slower the reaction to light so longer shutter speeds are required which, in turn, will affect the apertures you can use.
The ISO speed is fixed for film-based cameras. Those silver squares you see on the film casing tell the camera what the film's ISO speed is.
On digital cameras, the ISO speed determines how fast the sensor responds to light. This setting can be changed to any ISO setting the camera provides, so you have much more freedom in the pictures you can take. You could take one photo exposure at ISO 50 in good daylight conditions, the next one might be at ISO 1600 to bring out detail at night and so on.
Both film and CCD sesors suffer from grain. Both have fine granularity at low ISO settings and both have noticable grain at high ISO settings. So there is a trade-off between the amount of grain you want in your final image and the ISO speed that's called for in any given situation.
Focal Length
Lenses come in different focal lengths ranging from 16mm fisheye lenses through 28mm and 35mm wide angle lenses to the standard 50mm, and 135mm and 500mm telephoto lenses. And then you have the zoom lenses that traverse various focal lengths such as 28-80mm, 75-210mm and so on. Adorama have a huge selection of lenses and accessories, so you should find something there to suit your camera.
The actual definition of focal length is a bit technical. It's defined as the distance in mm from the optical center of the lens to the focal point, which is located on the sensor or film if the image is "in focus". The camera lens projects part of the scene onto the film or sensor. The field of view (FOV) is determined by the angle of view from the lens out to the scene and can be measured horizontally or vertically. Larger sensors or films have wider FOVs and can capture more of the scene. In other words, the longer the focal length, the closer objects appear through it and the smaller the area of the scene you can see (because you're zooming in on a smaller part of it).
Focal length affects the depth of field in your pictures which in turn affects the shutter speeds you can use, all of which are governed by the ISO speed you're using.
Metering
Your photo exposure is the key to successful landscape shots. You'll find a guide to the main metering options offered by SLR and creative compact cameras here.
One thing to beware of is burned out skies or dull featureless foregrounds. These occur when there's a large difference in brightness between the sky and the foreground. In such cases, you're better off using a graduated-filter to bring the brightess difference within the range that the film or digital sensor can record. Your first step is to determine the strength of filter you'll need. The simplest method is to take a meter reading with the ground filling the whole of the frame without the filter in place. Now repeat this step but this time with the sky filling the frame. The difference between these two readings will indicate the strength of graduated filter that you need. A 1-stop difference in the readings will need a 0.3 ND graduated filter, a 2-stop difference a 0.6 ND grad, while a 3-stop difference will require a 0.9 ND grad.
visit www.leenn.com
Saturday, June 21, 2008
Shooting Mode
What is Your Favorite Shooting Mode?
Are you an ‘Auto’ photographer? Do you use Aperture or Shutter Speed Priority Modes? Are you one of the few photographers who actually shoot in full Manual mode? Or are you the type of photographer who uses the preset shooting modes like ‘Landscape’, ‘Portrait’ or ‘Sports’?
There is no right or wrong answer on this one - it is possible to take great shots in any mode - but I’m always fascinated to see what people shoot in.
My personal preference these days is Aperture Priority Mode. It gives me enough creative control over things like depth of field but allows me to shoot quickly knowing that exposure will generally be right.
Automatic Modes
Automatic Mode
I suspect no one will need any introduction to this mode (as it seems most digital camera owners use it). Auto mode tells your camera to use its best judgment to select shutter speed, aperture, ISO, white balance, focus and flash to take the best shot that it can. With some cameras auto mode lets you override flash or change it to red eye reduction. This mode will give you nice results in many shooting conditions, however you need to keep in mind that you’re not telling your camera any extra information about the type of shot you’re taking so it will be ‘guessing’ as to what you want. As a result some of the following modes might be more appropriate to select as they give your camera a few more hints (without you needing to do anything more).
Portrait Mode
When you switch to portrait mode your camera will automatically select a large aperture (small number) which helps to keep your background out of focus (i.e. it sets a narrow depth of field - ensuring your subject is the only thing in focus and is therefore the center of attention in the shot). Portrait mode works best when you’re photographing a single subject so get in close enough to your subject (either by zooming in or walking closer) so that your photographing the head and shoulders of them). Also if you’re shooting into the sun you might want to trigger your flash to add a little light onto their face.
Macro Mode
Macro mode lets you move your closer into your subject to take a close up picture. It’s great for shooting flowers, insects or other small objects. Different digital cameras will have macro modes with different capabilities including different focusing distances (usually between 2-10cm for point and shoot cameras). When you use macro mode you’ll notice that focusing is more difficult as at short distances the depth of field is very narrow (just millimeters at times). Keep your camera and the object you’re photographing parallel if possible or you’ll find a lot of it will be out of focus. You’ll probably also find that you won’t want to use your camera’s built in flash when photographing close up objects or they’ll be burnt out. Lastly - a tripod is invaluable in macro shots as the depth of field is so small that even moving towards or away from your subject slightly can make your subject out of focus. (I’ll write a full tutorial on Macro Photography in the coming weeks).
Landscape Mode
This mode is almost the exact opposite of portrait mode in that it sets the camera up with a small aperture (large number) to make sure as much of the scene you’re photographing will be in focus as possible (ie it give you a large depth of field). It’s therefore ideal for capturing shots of wide scenes, particularly those witch points of interest at different distances from the camera. At times your camera might also select a slower shutter speed in this mode (to compensate for the small aperture) so you might want to consider a tripod or other method of ensuring your camera is still.
Sports Mode
Photographing moving objects is what sports mode (also called ‘action mode’ in some cameras) is designed for. It is ideal for photographing any moving objects including people playing sports, pets, cars, wildlife etc. Sports mode attempts to freeze the action by increasing the shutter speed. When photographing fast moving subjects you can also increase your chances of capturing them with panning of your camera along with the subject and/or by attempting to pre focus your camera on a spot where the subject will be when you want to photograph it (this takes practice).
Night Mode
This is a really fun mode to play around with and can create some wonderfully colorful and interesting shots. Night mode (a technique also called ’slow shutter sync’) is for shooting in low light situations and sets your camera to use a longer shutter speed to help capture details of the background but it also fires off a flash to illuminate the foreground (and subject). If you use this mode for a ’serious’ or well balanced shot you should use a tripod or your background will be blurred - however it’s also fun to take shots with this hand held to purposely blur your backgrounds - especially when there is a situation with lights behind your subject as it can give a fun and experimental look (great for parties and dance floors with colored lights).
Movie Mode
This mode extends your digital camera from just capturing still images to capturing moving ones. Most new digital cameras these days come with a movie mode that records both video but also sound. The quality is generally not up to video camera standards but it’s a handy mode to have when you come across that perfect subject that just can’t be captured with a still image. Keep in mind that moving images take up significantly more space on your memory storage than still images.
Other less common modes that I’ve seen on digital cameras over the past year include:
- Panoramic/Stitch Mode - for taking shots of a panoramic scene to be joined together later as one image.
- Snow Mode - to help with tricky bright lighting at the snow
- Fireworks Mode - for shooting firework displays
- Kids and Pets Mode - fast moving objects can be tricky - this mode seems to speed up shutter speed and help reduce shutter lag with some pre focusing
- Underwater Mode - underwater photography has it’s own unique set of exposure requirements
- Beach Mode - another bright scene mode
- Indoor Mode - helps with setting shutter speed and white balance
- Foliage Mode - boosts saturation to give nice bold colors
Aperture and Shutter Priority Modes
Over the last few weeks we’ve been looking at different elements of exposure and how to move out of the ‘Auto’ mode on your digital camera. We’ve looked at Aperture, Shutter Speed and ISO and have discovered what each of them is and what impact changing them will have on your images.
Now that we’ve looked at the theory of how changing these elements impacts an image I’d like to move into how to use them by examining two shooting modes that many digital have on them that allow you to take a step away from the automatic settings that you might be spending a lot of time in.
The two shooting modes are Aperture Priority Mode and Shutter Priority Mode.
A Quick Reviser
We’re looked at how the three elements of the exposure triangle impact one another. This is particularly the case when it comes to aperture and shutter speeds. As you increase the size of your aperture (make the hole that you shoot through bigger) you let more light into your image sensor. As a result you will need a shorter shutter speed. In the opposite way if you increase the length of time your shutter is open you decrease the necessary aperture that you’ll need to get a well exposed shot.
Priority Modes
Aperture and Shutter Priority modes are really semi-manual (or semi-automatic) modes. They give you some control over your settings but also ensure you have a well exposed image by the camera making some of the decisions on settings. Let me explain each separately:
Aperture Priority Mode
(often it has a symbol of ‘A’ or Av’ to indicate it’s selected)
In this mode you as the photographer set the aperture that you wish to use and the camera makes a decision about what shutter speed is appropriate in the conditions that you’re shooting in.
When would you use Aperture Priority Mode? How the main impact that aperture had on images was with regards to Depth of Field (DOF). As a result most people use Aperture Priority Mode when they are attempting to have some control in this area. If they want a shallow DOF (for example in the shot to the right which has the flower in focus but the background nice and blurred) they’ll select a large aperture (for example f/1.4 - as in the example to the right) and let the camera choose an appropriate shutter speed. If they wanted an image with everything in focus they’d pick a smaller aperture (for example f/22) and let the camera choose an appropriate shutter speed (generally a longer one).
When choosing an Aperture keep in mind that the camera will be choosing faster or longer shutter speeds and that there comes a point where shutter speeds get too long to continue to hand hold your camera (usually around 1/60). Once you get much slower than this level you’ll need to consider using a tripod. Also if you’re photographing a moving subject your shutter speed will impact how it’s captured and a slow shutter speed will mean your subject will be blurred).
Shutter Priority Mode
(Often has a symbol of TV or S)
In this mode you as the photographer choose the shutter speed that you wish to shoot at and let the camera make a decision about what aperture to select to give a well exposed shot.
When would you use Shutter Priority Mode? How the main impact of different shutter speeds was how ‘movement’ would be captured in your images. As a result most people switch to shutter priority mode when they want more control over how to photograph a moving subject.
For example if they want to photograph a racing car but want to completely freeze it so there is no motion blur they’d choose a fast shutter speed (say at 1/2000 like in the first shot below) and the camera would take into consideration how much light there was available and set an appropriate aperture. If instead you wanted to photograph the car but have some motion blur to illustrate how fast the car is moving you might like to choose a slower shutter speed (like the second shot below which has a shutter speed of 1/125) and the camera would choose a smaller aperture as a result.
Keep in mind that as the camera chooses different apertures it will impact the Depth of Field in your image. This means if you choose a fast shutter speed to freeze your fast moving object that it’ll have a narrower DOF.
Practice
As you can see - Shutter and Aperture Priority modes do give you more control over your images but they do take a little practice to get used to.
As you use them you need to not only think about the setting that YOU set but also keep an eye on the setting that the camera selects for you.
I find that when shooting in Av or TV modes that it’s often best to bracket your shots and shoot a number of images of the same subject (where you have time) at different settings. This will ensure that you’re likely to get at least one shot which meets your need.
The best way to learn about Shutter priority and Aperture Priority modes is to grab your camera, to head out with it and to experiment. Switch to Av or TV and start playing with the different settings (taking lots of shots as you go). Particularly watch how the camera makes changes to compensate for your selections and what impact it has upon the shots that you take.
In Aperture Priority Mode take some shots at the largest aperture you can (small numbers) and see how it blurs the background (but also increases the shutter speed) and then head to the other end of the spectrum to take some shots at the smallest aperture you can (large numbers) to see how it keeps more of your image in focus.
In Shutter Priority Mode play with fast and slow shutter speeds and see how that impacts DOF.
Don’t be frustrated if your initial shots are not what you’d expect - it takes practice to get your head around these modes. But keep in mind that when you do master them you’ll have a lot more creative control over your shots. It’s really worth learning this.
What mode do you shoot in most?
Grab your digital camera and check something for me. Look at the dial/switch/menu that shows you which shooting mode you’re currently in and let us know what it is.
I’m fascinated by watching how others use their cameras and am particularly interested to see what modes they use by default.
Are you an ‘Auto’ photographer? Do you use Aperture or Shutter Speed Priority Modes? Are you one of the few photographers who actually shoot in full Manual mode? Or are you the type of photographer who uses the preset shooting modes like ‘Landscape’, ‘Portrait’ or ‘Sports’?
There’s no right or wrong answer - but I’d love to hear what your camera is set to right now and whether that’s a ‘normal’ mode for you? Answer in comments below.
Let me share my own preference:
What mode do I shoot in?
I’m an ‘Aperture Priority Mode’ kind of guy.
I personally like it because I find it gives me the type of creative control that I want on how my images look - specifically over depth of field.
The only time that I really switch over to another mode is when I’m shooting moving objects and need a faster (or slower) shutter speed (to capture some motion blur or freeze the motion completely).
Friday, June 20, 2008
Choosing a Canon lens and basic lens categories
Choosing a Canon lens and basic lens categories.
Why doesn’t my camera just come with a lens? Isn’t that kind of cheap?
No. It’s actually a good thing. First of all, the whole point of a camera with interchangeable lenses is you can attach whatever lens you need. Unlike a simple point and
shoot with its non-removable lens you aren’t limited to whatever the manufacturer builds into the camera. Second, everyone has different needs and budgets. So it’s
usually desirable not to include a lens so you can choose the lens or lenses which are right for you, not some generic lens. Third, what if you were to buy another
camera? Then you would have two of the same lenses.
Having said that, Canon do sell many EOS cameras bundled with included lenses. Such lenses are called kit lenses, but frankly not all kit lenses are of a particularly
high quality. You’re often best off buying the camera body which suits your needs and finding a good lens to match it.
What are wide-angle, normal and telephoto lenses?
We’ve all had the experience before. You’re trying to take a photograph of some friends, but you just can’t fit everybody into the picture. You step backwards further,
but there’s a wall or cliff or something, and it just isn’t going to work, so you tell your friends to squeeze in closer. Or you see a bird flying by in the distance, you grab
your camera, and you end up with a big photograph of sky with a disappointingly tiny little dot in the middle of the frame.
In each case the field of view provided by the lens isn’t appropriate for your subject matter. In the first instance your lens is not “wide” enough to take in the whole
scene, and in the second your lens isn’t “long” enough. There are three rough categories of lenses when it comes to how much of a scene they can take in, and the
field of view of each type is defined by an optical property known as the focal length of the lens (a property explained later in this document).
• A so-called normal lens roughly approximates the perspective, though not the area of, a scene seen by one human eye. By convention a normal lens on a
35mm film camera (and thus a full-frame EOS digital SLR) has a focal length of 50mm or so. Think of normal lenses as being good for taking pictures in close, but not
intimate, proximity to a subject, like a waist-up picture of a person in an ordinary room.
• A wide-angle lens can take in a large area of a scene. This has two common applications - first, it means you can take in sweeping panoramic landscape
scenes, and second, you can take in large areas of an ordinary room. If you want to take a photo of a group of friends at a dinner party you’ll need a wide angle lens
unless you can back up far enough to get everyone in. On a 35mm film camera a wide angle lens would have a focal length of, say, 35mm or less.
• Looking through a telephoto lens is like using a telescope - it narrows down what can be seen in a scene or makes the subject seem much closer than it
really is. A telephoto lens might have a focal length of 70mm or more on a 35mm camera.
Note one area of potential confusion - there are different measurements expressed here in millimeters, but which refer to two different physical properties. In the
case of 35mm film cameras, we’re talking about the width of the film material. But in the case of, say, an 80mm lens, we’re talking about its focal length. You can thus
put a 28mm lens on a 35mm camera - the measurements are about different things.
These are just broad categories, of course, and there are big variations in each one. You can get an inexpensive 28mm lens, for example, which is only modestly wide.
Or you can get a crazy expensive 14mm lens which can take in a huge area of a scene - perfect for shots of ultra-dramatic skies. Similarly you could put an 85mm lens
on your camera for portrait photography, or you could sell your car and buy a huge 600mm lens that requires a large suitcase for transportation but which lets you
take a closeup of a bird’s face from a huge distance away.
What’s the difference between a zoom lens and a fixed focal length (prime) lens?
A prime lens is a lens in which the field of view (focal length) cannot be adjusted. The only way to take in more or less of the scene is to walk closer to or further from
the subject. (Sometimes called “zoom with your feet,” though this is technically inaccurate since changing camera position is not the same thing as adjusting the focal
length) Or you have to carry a selection of lenses of different focal lengths with you and swap them out as required.
A zoom lens is a lens in which the field of view can be adjusted. If you can’t fit in all your friends in the picture, for example, you could just rotate the zoom ring on the
lens until they’re all in there. Or if that bird is too far away you could rotate it the other way to zoom in closer.
Up until the late 1980s prime lenses were the most common lens sold, because from an optical design standpoint it’s much easier to design a high quality prime lens
that can take nice sharp photographs than a decent quality zoom lens. But a prime is also obviously a lot less convenient, since you have to move around more to fit
stuff in. So by the late 80s zoom lenses became more and more popular. Today hardly any low-cost lenses are prime lenses, because everybody wants zooms.
So why buy a prime lens at all? Well, for the same reason as ever - prime lenses are easier to build and offer fewer compromises in design. If you want a really sharp
crisp lens, then a good prime will offer sharper pictures than most zooms. Or if you want a lens that can let in lots of light and thus can be used for low-light
photography then you’ll probably want a prime, since it’s much harder to build a “fast” (lets in lots of light) zoom lens. And some crusty old photographers also argue
that using prime lenses is very important for novice photographers since it forces them to learn about the importance of focal lengths and perspective.
Lens construction is thus always about tradeoffs. You may want a lens that’s small, lightweight, has zoom capabilities, lets in lots of light, is really sharp, has high
contrast, doesn’t distort the image and is cheap. But in real life you can only get some of those properties - it’s impossible to get all of them, sadly.
Most amateurs on a budget choose the flexibility of low-cost zoom lenses over picture quality as their compromise. Many advanced amateurs choose the higher
picture quality of affordable primes and deal with the inconvenience as theirs. And many professionals buy high quality zooms that weigh a ton and cost piles of money
as theirs.
Note one common misconception - a lot of people think zoom lenses are used for taking photos of things far away. That’s actually a better description of a telephoto
lens, as described above.
Which lens should I buy for my camera?
As with buying a camera there are a lot of things to consider, so this question really can’t be asked without asking many more questions first. Here are some of them:
What exactly are you going to be photographing?
Your photographic goals and objectives essentially inform all of the other decisions. Will you being shooting landscapes? Portraits? Your kids or pets? Flowers? Wild
birds? Sports? Architecture? Will you be doing travel photography? Will you be hiking with your gear? These sorts of questions are critical to ask yourself first.
How much money do you want to spend?
You can spend huge amounts of money on lenses, so determining your budget, as with cameras, is pretty important.
Do you want to buy a used or a new lens?
The same questions apply as when purchasing a new or used camera.
Do you want a prime (fixed focal length) or a zoom (variable focal length) lens?
Prime lenses generally afford higher optical quality than zooms, except in the case of really expensive pro zoom lenses. However prime lenses mean you have to walk
around more - you can’t simply adjust the zoom setting to get the framing you need.
What focal length or focal length range do you want to cover?
I’d sit down with your photos and think about what focal lengths you tend to use most and where there are gaps. Maybe you want an extreme wide angle, for example.
If so there’s no point getting another telephoto.
Do you need a fast lens?
Do you want to do low-light photography without a tripod or flash? Do you want to do portrait photos while blurring the background? These applications call for a
faster lens which can let in more light.
Do you want to buy Canon-built or third party lenses?
Third party makers build many great lenses, but many are also really poor - you have to do some research. And others have compatibility problems with existing
cameras or may have future compatibility problems. Are the price savings worth it for the specific lens you’re interested in?
Do you care about the user interface and build quality?
A lens may be slow to focus or inconvenient to use but offers higher optical quality than another lens with a faster motor and a better designed UI. Ring USM motors
are fast, silent and offer full-time manual override, but lenses containing such motors tend to cost more than slower, noisier non-FTM arc-form (AFD) motors.
What aspect of optical quality is important to you?
Obviously sharpness and contrast are pretty important to most people, but what about distortion? Many consumer zooms have a lot of distortion, making them
unsuitable for architectural photography. They also tend to be more vulnerable to flare (lowering contrast or resulting in bright spots on the picture if a bright light like
the sun is in or near the frame) and tend to have very slow maximum apertures.
Which lens should I buy for my EOS digital camera?
There are two things that are important to keep in mind when shopping for lenses for an EOS digital camera, such as the EOS 10D, rather than an EOS film camera.
First, EOS digitals are still not as cheap as film cameras, so don’t just try to find the cheapest lens you can. And if you’re going to be shelling out this much money for
the camera body, buying the cheapest lens you can find is not merely false economy, it’s downright foolish, if you ask me.
It’s like spending massive amounts of money on a high-end CD player and amplifier and then plugging them into a pair of toy loudspeakers. Just as the final sound of
your music will be hobbled by the toy loudspeakers the final quality of your pictures will be hobbled by a cheap lens. So avoid lenses in the “cheapie” category (see
below).
Second, with the exception of the cropping factor the selection criteria for buying a lens for a digital camera really don’t differ much from the criteria for buying a lens
for a film camera. What type of photography do you want to do? Do you need a wide angle for landscapes? A fast-focusing telephoto for sports? A sharp and short
telephoto for portraits? How much weight do you want to carry around? These questions are the same regardless of whether you want to shoot film or digital - check
the list above.
But as noted, there is one major difference to keep in mind with most digital EOS cameras - the cropping factor, also known as the focal length multiplier. With the
exception of the EOS 1Ds, 1Ds mark II and 5D, which have full-size image sensors equivalent in size to a 35mm EOS film camera, most current EOS digital cameras
use image sensors smaller than a 35mm film frame. If your camera has a cropping factor of 1.6x it means that, say, a lens with a 50mm focal length will suddenly
behave rather like a lens with an 80mm focal length. The focal length of the lens does not change, but its apparent effect does. (since the image sensor is smaller,
think of it as simply snipping off all four sides with a pair of scissors, resulting in a smaller picture, and then enlarging the picture on a photocopier)
This issue has two nice advantages. First, you can buy a cheap 50mm lens and use it as a very nice portrait lens. Second, you can attach a telephoto to your camera
and it’ll behave like a much longer telephoto - you’ll have much more reach. The drawback, of course, is that wide angle pictures are harder to achieve as you need
much wider lenses for such photos. This can be a significant problem for many people.
So with such digital cameras you will probably want to get a lens that’s a bit wider than you would if you were buying for a 35mm film camera. If you use a 28-105mm
lens on your 35mm camera, for example, you might get a 24-85mm lens instead.
The one question related to this is whether the EF-S 18-55 lens (see next section) included with the EOS 300D/Digital Rebel/Kiss Digital kit is worth it. The
consensus is that it’s definitely worth the small increase in price over the body only. The EF-S 18-55 is no L series lens by a long shot, but it offers surprisingly decent
optical quality for the incredibly low price, and it’s the only affordable way to get down to moderately wide angles (roughly the same as a 29mm lens on a 35mm film
camera) on the 300D.
One final issue with digital is that some newer lenses have coatings which work a bit better with digital image sensors than those used on older lenses. Generally
speaking this is a fairly subtle issue, advertising notwithstanding.
What is an EF-S lens?
From essentially the introduction of the EOS camera system in 1987 through to 2003 Canon standardized on a single lens mount system for all of their SLR cameras -
the EF (electro focus) lens mount. So throughout this time there was no possible source of confusion, since all EF lenses made by Canon and other lens makers will
physically fit all Canon EOS cameras.
However, in 2003 Canon introduced a new digital camera, the consumer-oriented EOS 300D/Digital Rebel/Kiss Digital camera, which sported a new lens mount
design dubbed EF-S. All consumer to midrange digital EOS cameras released since have been both EF and EF-S compatible. For reasons explained in a moment, no
film camera has ever been EF-S compatible.
So it’s important to remember that digital camera bodies with EF-S lens mounts are totally compatible with all regular EF lenses. However an EF-S lens can fit only
EF-S compatible cameras and no others. (unless the lens is altered - see the section on hacking below).
EF-S bodies have small mirror boxes - roughly 2/3 the size of a regular EOS camera (also known as a 1.6x cropping factor) - because they use image sensors which
are smaller in area than 35mm film. They, and APS cameras which similarly used small imaging areas, are thus often called sub frame cameras. Cameras which use
35mm film or which use large sensors that are the same size as a frame of 35mm film are commonly called full frame cameras these days.
EF-S cameras thus support lenses with a shorter back focus distance than EF lenses, because the mirror swings further back. This is where the “S” comes from -
EF-S lenses have shorter back focus distances. (ie: the back part of the lens can get physically closer to the image sensor since the mirror is smaller) Having a
shorter back focus distance allows Canon to produce cheaper wide-angle lenses that work with the smaller image format of a sub frame digital SLR, since it’s
optically very challenging to create a wide angle lens with a long back focus distance.
Canon have a small but growing series of EF-S lenses available, ranging from inexpensive kit lenses to very good high-quality lenses with image stabilization. There’s
even a very interesting 60mm macro lens with an EF-S mount. The super wide angle EF-S 10-22mm 3.5-4.5 USM (roughly 16-35mm coverage if it were full frame) is
particularly well regarded, as is the EF-S 17-55 2.8 IS USM, which is an L lens in all but build quality and name.
The main issue to be concerned about with EF-S is the future value of the lenses. Right now full-frame image sensors are extremely expensive to make, which is why
nearly all digital SLRs out there have image sensors smaller than that of a frame of 35mm film. But in the future it’s likely that prices on such sensors will drop, at
which time full-frame digital SLRs will become more affordable and thus EF-S lenses will no longer be of use except on pre-existing cameras. The two questions are -
how long will this take and will you be able to get good use of your investment in EF-S lenses before this occurs? The first nobody knows the answer to, and the
second can only be answered by you. For the time being it seems likely that it’ll be some years before affordable full-frame sensors are ubiquitous, so EF-S lenses
aren’t necessarily a bad idea, assuming you aren’t planning on upgrading to full-frame as soon as you can.
Can my camera take EF-S lenses?
Any Canon EOS camera with a red dot on the lens mount can take EF lenses. Any Canon EOS camera with both a red dot and a white square on the lens mount can
take both EF lenses and EF-S lenses.
What you see is what you get
This whole discussion about focal lengths and EF versus EF-S can be very confusing if you’re a beginner. The key thing to remember if you’re just starting out is what
you see is what you get. When you look through the viewfinder you’re going to see pretty well exactly what will be in the photograph - minus a tiny little strip along
each edge on consumer cameras. So there’s no need to worry about mathematical calculations and whatnot to figure out what will be in your picture and what won’t.
The only time the whole cropping factor is really an issue is when you’re comparing how much of a scene (coverage angle) is taken in by an EF lens on a full-frame
camera, compared to an EF lens on a cropped body, or compared to an EF-S lens on an EF-S compatible camera. For guidance on this, take a look at my Complete
EOS Lookup Page. It allows you to compare multiple lenses to see how much of a scene each lens can take in when used on cropped or full frame bodies.
Distinguishing EF from EF-S
Regular EF bodies and lenses use raised red dots for aligning lens and body. EF-S bodies have a white square as well, which must be lined up to the white square on
EF-S lenses. Interestingly enough, EF-S lenses also have rubber rings around the end which press up against the interior of the camera body. This is not as
sophisticated as the weather seals used in L series lenses, but presumably helps reduce dust levels inside the camera slightly. Also, according to Canon, this ring
minimizes damage if you were to try and mount an EF-S lens on a EF-only camera.
Full frame equivalent
You’ll sometimes see phrases such as “full frame equivalent” or “35mm equivalent” in conjunction with lenses designed for subframe sensors, such as EF-S lenses.
Properly speaking these are not equivalent values for a variety of technical reasons, but they are nonetheless useful points of reference. For instance, a 60mm EF-S
lens has the same field of view as a 96mm lens on a 35mm film camera. So sometimes 60mm EF-S lenses are said to have a full-frame equivalent field of view of
96mm.
EF-S lenses and film cameras
No EOS 35mm film camera has or is ever going to use an imaging area smaller than 36x24mm, so no EOS 35mm film camera will ever be able to support EF-S lenses.
Even if you were to attach one somehow the mirror would collide with the back of the lens when it flipped up, and the lens would vignette severely because EF-S
lenses can’t image an image circle as large as 35mm film. In theory Canon might be able to build an APS camera with support for EF-S lenses, since APS film uses a
surface area smaller than that of 35mm film, but since APS is a commercially moribund format that isn’t ever going to happen. So the only cameras you’ll ever see
with EF-S lens mounts are going to be digital.
Hacking EF-S lenses
While EF-S lenses are not designed to fit EF-only cameras, it is possible to saw off or, in some cases, unscrew the back of an EF-S lens and attach the lens to any
EOS camera. The problem is that if you put a modified EF-S lens on an EOS camera with a standard sized mirror box then the mirror will flip up and smash into the
lens when you try to take a photo. So modified EF-S lenses will only work with older EOS digital cameras with cropping factors of 1.6x that predate the EF-S system:
namely the EOS D30, D60 and 10D. Even then there are risks. For example, at its widest position the EF-S 10-22mm lens collides with the mirror in non-EF-S
compatible cameras, even those with small mirror boxes. (for this reason it’s unwise to use a modified EF-S lens on a 1.3x digital camera such as the 1D) Messing
around in this fashion is fun - I’ve done it myself and it works well - but obviously invalidates your Canon warranty and runs the risk of breaking something.
What are all these numbers printed on my lens?
Lenses have bits of text printed on the barrel or around the front element which convey a lot of important information about their properties. Be really careful when
shopping for lenses. Two lenses may have very similar-looking names, but may actually be completely different one from the other.
Here are two examples. Note that all the technical terms used here are described later on in this FAQ.
CANON LENS EF 28-80mm 1:3.5-5.6. Ø58mm.
EF means that the lens is of the Canon EF type. EF lenses fit Canon EOS cameras and virtually no others.
28-80mm refers to the focal length of the lens. In this case there are two values since the lens is a zoom lens which can go from 28mm at its widest to 80mm at its
longest. These numeric values in millimeters essentially indicate the coverage area of the lens.
1:3.5-5.6 refers to the widest aperture of which the lens is capable. The 1: is there since f/stops are, technically speaking, ratios. Since the lens is a zoom there are two
aperture values - f/3.5 and f/5.6. This particular lens is an inexpensive amateur lens which can be opened up to f/3.5 at the widest end (28mm) but only f/5.6 at the
longest end (80mm). This means it’s a fairly slow lens - it can’t let in much light, even when its aperture diaphragm is fully open.
Note that the autofocus motor type is not indicated, which means that the lens uses either an AFD (arc-form drive) or micromotor drive. Both types are slow and noisy
compared to ultrasonic (USM) motors.
Ø58mm refers to the filter ring diameter. In other words, screw-on filters 58mm in diameter will fit this lens.
CANON LENS EF 200mm 1:2.8L II USM. Ø72mm.
EF means that the lens is a Canon EF lens for EOS cameras.
200mm refers to the focal length. Since only one value is indicated, this lens is a prime lens (ie: a lens with a fixed focal length).
1:2.8 refers to the widest aperture of which the lens is capable. f/2.8 is reasonably wide, especially for a 200mm telephoto lens, and so this is considered a fast lens.
L indicates that the lens is an L or “luxury” series Canon lens. Such lenses are generally the best that Canon manufacture. They are marked with a characteristic red
stripe around the end of the lens barrel.
II indicates that this is the second version of this lens with these particular numerical specifications that Canon have made.
USM refers to the autofocus motor type used by the lens. In this case it uses an ultrasonic motor - see below. Non-L USM lenses are marked with a characteristic
gold stripe around the end of the lens barrel. L lenses usually have USM motors, but have a red stripe instead (ie: the red stripe takes priority and you don’t see
lenses with two stripes).
Ø72mm refers to the filter ring diameter. In other words, screw-on filters 72mm in diameter will fit this lens, making it a fairly large lens.
What is a Canon L-series lens and why is it a big deal?
Canon sell a number of lenses in a special series they refer to as L for “luxury.” These are their most expensive and highest-quality lenses, and are readily
identifiable by the red stripe painted around the end of the barrel.
L series lenses offer higher optical quality than their non-L equivalents, and have an important technical aspect in common. At least one element in every L lens is
either made of fluorite crystal rather than glass, is a ground aspheric lens element (not a moulded/replicated aspheric lens as used in less expensive lenses) or is
made from ultra-low dispersion glass. Most L series lenses are also sturdily built - many are encased in metal barrels and are weatherproofed - and most are very
fast lenses for their focal lengths. Nearly all telephoto L series lenses are also off-white rather than black.
These lenses are, therefore, marketed as professional camera lenses and are usually priced out of the range of most consumers. They can be used to take great
photographs, but the cost, weight and size of these lenses are the tradeoffs.
Of course, a lens doesn’t have to be an L series lens to take good pictures. Many EOS lenses offer excellent optical quality - they just don’t need and thus don’t have
exotic fluorite lens elements and so on. Many of Canon’s prime lenses in the 35mm to 135mm range fit in this category - see below. And some recent EF-S lenses
offer near-L image quality but lack the red ring and the tough build quality of contemporary L series lenses.
Note also that the presence of a red ring around the end of a lens barrel only indicates an L series lens if it’s actually made by Canon. Some other makers happily
paint red stripes around the end of their lenses too, but this in no way guarantees that the lens meets the quality standard of a Canon L lens.
What other general categories of Canon EOS-compatible lenses are there?
In addition to the aforementioned L series lenses most other Canon EF lenses fall into a number of broad categories. Note, however, that these are not official
Canon-named categories. As far as Canon is concerned, EF lenses come in two categories - L and all the rest. Nonetheless these informal categories are useful to
keep in mind when lens shopping.
Category 1 - consumer lenses.
At the bottom of the consumer line are the cheapies - ultra-low cost, low-quality, slow lenses with plastic mounts and no distance scales. Most of the kit lenses - 28-80
and 28-90 lenses with typical aperture ranges of 4.0 to 5.6 - fit into this category. These lenses are built to be sold as inexpensively as possible and don’t have very
good optical quality. The only exception to this basic rule is the 50mm 1.8 II - plastic lens mount - which has excellent optical quality despite its cheap build quality,
because it isn’t a zoom lens like all the others. The cheapies are easily recognizable by their all-plastic construction and straight, parallel-sided lens barrels. Most of
the late-model cheapies are identified by the silver (chrome) ring around the end.
Am I being a huge snob by calling them “cheapies”? Maybe, but the point is that Canon optimize these lenses for cheapness. They want products to sell in massive
numbers in shopping mall/high street camera shops and department stores. This market does not, it seems, place a great deal of value on image quality - cheap prices
for impulse buys are everything. That’s great for Canon’s balance sheet, but frankly, if I’m going to be dealing with the hassle of carrying around an SLR camera I
want at least half-decent optical quality for the attached lens. Otherwise I think it’s a lot easier just to carry around a cheap lightweight point and shoot camera.
Category 2 - midrange zooms.
In the midrange are better lenses with improved optics, sturdier build quality, metal mounts and distance scales. These often have ring USM motors. The 24-85
3.5-4.5 USM, 28-105 3.5-4.5 USM and 100-300 4.5-5.6 USM are typical examples. They’re decent consumer lenses but don’t have the optical clarity of the pro
lenses, especially when shooting wide open. However, they generally cost a fraction of the price of the top of the line stuff. These lenses are generally fairly elegantly
designed, with slightly rounded and tapered lens barrels, and usually have easy to grip ribbed rubber zoom rings rather than bare plastic.
There are also older low-end zooms with decent optical quality, such as the 28-70 3.5-4.5 II, which don’t use modern USM drives but which nonetheless offer good
value for money on the used market.
Category 3 - inexpensive primes.
Canon also sell and have sold a number of prime (ie: non zoom) lenses with acceptable optics and average build quality (usually with noisy motor drives, metal mounts
and distance scales), such as the 28mm 2.8 and 50mm 1.8 (metal lens mount). Despite their low cost and pretty unremarkable construction they can provide quite good
photographic results.
All lenses in this category are mostly normal or near normal lenses - no super wide angles and no long telephotos. The designs generally date back to the early days
of the EOS lineup, so they tend to look a bit old-fashioned, style-wise. Canon just haven’t seen the need to update any of them.
Category 4 - good primes.
This is a group of prime lenses which offer excellent optics and decent build quality, but which don’t really need and thus don’t use ultra low-dispersion glass or
calcium fluorite crystals or other hallmarks of L-class lenses. Remarkably good lenses like the 85mm 1.8 and the 100mm 2.8 macro fit into this category. Most have
ring ultrasonic motors. They generally resemble the category 2 lenses - slightly rounded and tapered lens barrels. Optically they are professional lenses in all but the
name, though they’re usually not quite as heavy-duty as the fancier L lenses.
Category 5 - specialized lenses.
Canon also make a handful of expensive specialized lenses for unusual applications which I’ll just lump into this category for lack of anywhere else to put them. These
include their tilt-shift TS-E lenses, the MP-E 65mm super-macro lens and the DO (diffractive optics) lenses.
Which lens falls in which category?
Here’s a list of most Canon EOS-compatible lenses - both current and discontinued - sorted according to the categories above. Lenses are EF lenses (all EOS
cameras) except those marked EF-S, which fit only EF-S-compatible digital EOS cameras.
The numeric value marked with the Ø symbol is the filter mount diameter. In other words, round screwmount filters of the size indicated can be attached to this lens. A
few lenses - the extreme wide-angle lenses and the really long telephotos - use drop-in or gelatine filters inserted into the lens barrel.
Many lenses have the word “Macro” marked on them but only those identified here as macro are true macro lenses. True macro lenses are defined as those lenses
capable of 1:1 focussing or better. The only Canon macro lens which doesn’t quite fit this definition is the 50mm 2.5 Compact Macro, which requires the add-on
Life-Size adapter to reach 1:1.
Check out Canon’s Camera Museum site for technical details on all the EF lenses that Canon has ever produced.
Category 1 - cheapies.
These inexpensive lenses feature all-plastic barrel construction with plastic lens mounts (the 75-300 series and the 28-200 lenses being exceptions - they have metal
mounts) and no distance scales. Those lenses in this category which have ultrasonic motors (USM) use cheaper micromotor USM, not ring USM. USM lenses are
marked with a striped gold line around the end. Some of these lenses also have silver (chrome) rings around the end for good looks. Most lenses in this category
support optional manual focussing, but their manual focus rings are usually awkward and cumbersome to use.
EF-S 18-55 3.5-5.6, Ø58
Inexpensive EF-S kit lens; reasonable optical quality
EF-S 18-55 3.5-5.6 USM, Ø58
Apparently only sold in Japan
EF-S 18-55 3.5-5.6 II, Ø58
Cosmetic update to the above
22-55mm 4.0-5.6 USM, Ø58
28-105mm 4.0-5.6, Ø58
28-105mm 4.0-5.6 USM, Ø58
28-80mm 3.5-5.6, Ø58
28-200mm 3.5-5.6, Ø72
28-200mm 3.5-5.6 USM, Ø72
28-80mm 3.5-5.6, Ø58
28-80mm 3.5-5.6 II, Ø58
28-80mm 3.5-5.6 II USM, Ø58
28-80mm 3.5-5.6 III, Ø58
28-80mm 3.5-5.6 III USM, Ø58
28-80mm 3.5-5.6 IV USM, Ø58
28-80mm 3.5-5.6 V USM, Ø58
28-90mm 4-5.6, Ø58
28-90mm 4-5.6 USM, Ø58
28-90mm 4-5.6 II, Ø58
28-90mm 4-5.6 USM II, Ø58
Silver-coloured
35-70mm 3.5-4.5 A, Ø52
Autofocus only - no manual focus ring
35-80mm 4-5.6, Ø52
35-80mm 4-5.6 PZ, Ø52
Powered (motorized) zoom
35-80mm 4-5.6 II, Ø52
35-80mm 4-5.6 III, Ø52
35-80mm 4-5.6 USM, Ø52
35-105mm 4.5-5.6 USM, Ø58
38-76mm 4.5-5.6, Ø52
55-200mm 4.5-5.6 USM, Ø52
55-200mm 4.5-5.6 II USM, Ø52
75-300mm 4-5.6, Ø58
75-300mm 4-5.6, Ø58
75-300mm 4-5.6 II, Ø58
75-300mm 4-5.6 II USM, Ø58
75-300mm 4-5.6 III, Ø58
75-300mm 4-5.6 III USM, Ø58
75-300mm 4-5.6 USM, Ø58
80-200mm 4.5-5.6, Ø52
80-200mm 4.5-5.6 II, Ø52
80-200mm 4.5-5.6 USM, Ø52
90-300mm 4.5-5.6, Ø58
90-300mm 4.5-5.6 USM, Ø58
100-200mm 4.5 A, Ø58
Autofocus only - no manual focus ring
Category 2 - midrange zooms.
All lenses in this category have metal lens mounts, and come in two basic flavours - old-style lens barrel and new style. The old style feature hard textured plastic
barrels with narrow focus rings and their AF/MF switches are low and sometimes difficult to adjust. The new style feature slightly more resilient shiny plastic with
wider focus and zoom rings, often with lots of easy-grip ribbed rubber. The new style lenses also boast ring USM focus drives and easier to operate AF/MF switches.
EF-S 10-22mm 3.5-4.5 USM, Ø77
Unusually for a lens not marketed as L series, this lens contains a Super UD element and has very good image quality.
EF-S 17-85mm 4-5.6 IS USM, Ø67
EF-S 17-55 2.8 IS USM, Ø77
This is an interesting lens since it actually has L-series image quality thanks in part to the use of UD glass. However, build quality is on par with better consumer
lenses and not L series lenses.
20-35mm 3.5-4.5 USM, Ø77
24-85mm 3.5-4.5 USM, Ø67
Available in silver or black
28-70mm 3.5-4.5, Ø52
28-70mm 3.5-4.5 II, Ø52
28-80mm 3.5-5.6 USM, Ø58
(unlike later all-plastic II and higher models, these lenses have a metal mount)
28-105mm 3.5-4.5 “Macro” USM, Ø58
28-105mm 3.5-4.5 II “Macro” USM, Ø58
28-135mm 3.5-5.6 IS “Macro” USM, Ø72
35-70mm 3.5-4.5, Ø52
Old-style barrel
35-105mm 3.5-4.5 “Macro”, Ø58
Old-style barrel, push-pull zoom
35-135mm 4-5.6 USM, Ø58
50-200mm 3.5-4.5, Ø58
Old-style barrel
70-210mm 3.5-4.5 USM, Ø58
70-210mm 4 “Macro”, Ø58
Old-style barrel, push-pull zoom
70-300mm 4-5.6 IS USM, Ø58
The replacement to the 75-300 4-5.6 IS USM
75-300mm 4-5.6 IS USM, Ø58
Optically a cheapie, but image stabilization moves it up a category
100-300mm 4.5-5.6 USM, Ø58
100-300mm 5.6 “Macro”, Ø58
Old-style barrel, push-pull zoom
Category 3 - inexpensive primes.
With the exception of the all-plastic (including plastic lens mount) 50mm 1.8 mark II, the inexpensive primes all have old-style lens barrels - hard textured plastic, a
narrow focussing ring and distance scale.
28mm 2.8, Ø52
35mm 2, Ø52
50mm 1.8, Ø52
50mm 1.8 II, Ø52
Plastic lens mount, no distance scale but same good optics as the 50mm 1.8
Category 4 - good primes.
As with the midrange zoom lenses, the good primes are available in either old-style lens barrel designs or new-style.
15mm 2.8 fisheye
Old-style barrel
20mm 2.8 USM, Ø72
New-style barrel
24mm 2.8, Ø58
Old-style barrel
28mm 1.8 USM, Ø58
New-style barrel
50mm 1.4 USM, Ø58
New-style barrel
50mm 2.5 Compact macro, Ø52
True (1:2; 1:1 with adapter) macro, old-style barrel
EF-S 60mm 2.8 USM macro, Ø52
EF-S only true 1:1 macro lens
85mm 1.8 USM, Ø58
New-style barrel
100mm 2 USM, Ø58
New-style barrel - do not confuse with the 100mm 2.8, which is a macro lens
100mm 2.8 Macro, Ø52
True 1:1 macro, old-style barrel
100mm 2.8 Macro USM, Ø58
True 1:1 macro, new-style barrel
135mm 2.8 SF, Ø52
Old-style barrel, adjustable soft focus control
Category 5 - specialized lenses.
Unusual, expensive and specialized lenses.
MP-E 65mm 2.8 1-5x Macro
Powerful macro lens, for closeups only
TS-E 24mm 3.5 L, Ø72
Tilt-shift, manual focus only
TS-E 45mm 2.8, Ø72
Tilt-shift, manual focus only
TS-E 90mm 2.8, 58
Tilt-shift, manual focus only
EF 70-300 4.5-5.6 DO IS USM
Diffractive optics. Marked with a green ring
EF 400mm 4 DO IS USM
Diffractive optics. Marked with a green ring
L series lenses
All L series lenses are easily identifiable by the red ring around the end of the barrel and the letter L at the end of their technical designations.
Most L series lenses are heavy shiny black plastic or white-painted metal. Most newer lenses (since 1999 or so) are weather-sealed though some (the earliest L
series) are textured black plastic. The handful of early L series lenses with old-style barrels are not built to the same tough build quality of modern L lenses, though
optically they’re fine.
Most L series lenses are large and fast lenses and thus quite expensive. However in the past few years Canon have also released a few more affordable L series
zooms. These lenses are optically slower f/4 lenses which are smaller, lighter and cheaper than their f/2.8 counterparts. No L series lens has ever been made with an
EF-S lens mount: they are always EF lens mounts only.
14mm 2.8 L USM
24mm 1.4L USM
16-35mm 2.8 L USM, Ø77
16-35mm 2.8 L II USM, Ø82
17-35mm 2.8 L USM, Ø77
17-40mm 4 L USM, Ø77
20-35mm 2.8 L, Ø72
24-70mm 2.8 L USM, Ø77
24-105mm 4 L IS USM, Ø77
28-70mm 2.8 L USM “Macro”, Ø77
28-80mm 2.8-4 L USM, Ø72
28-300mm 3.5-5.6L IS USM, Ø77
35mm 1.4 L USM, Ø72
35-350mm 3.5-5.6 L USM, Ø72
50mm 1 L USM, Ø72
50mm 1.2 L USM, Ø72
50-200mm 3.5-4.5 L, Ø58
Old-style barrel, push-pull zoom
70-200mm 2.8 L USM, Ø77
70-200mm 2.8 L IS USM, Ø77
70-200mm 4 L USM, Ø67
70-200mm 4 L IS USM, Ø67
80-200mm 2.8L
Old-style barrel; not compatible with teleconverters
85mm 1.2 L USM, Ø72
85mm 1.2 L USM II, Ø72
100-300mm 5.6 L, Ø58
Old-style barrel, push-pull zoom
100-400mm 4.5-5.6 L IS USM, Ø77
Push-pull zoom
135mm 2 L USM, Ø72
180mm 3.5 Macro L USM, Ø72
True 1:1 macro
200mm 1.8 L USM
200mm 2.8 L USM, Ø72
200mm 2.8 L II USM, Ø72
300mm 2.8 L USM
300mm 2.8 L IS USM
300mm 4 L USM, Ø77
300mm 4 L IS USM, Ø77
400mm 2.8 L USM
400mm 2.8 L II USM
400mm 2.8L L IS USM
400mm 5.6L USM
500mm 4 L IS USM
500mm 4.5 L USM
600mm 4 L USM
600mm 4 L USM II
1200mm 5.6L USM
What’s wrong with the “kit” lens included with my camera? Why do you call it a cheapie?
Don’t take it personally. Canon sell most of their inexpensive consumer cameras either as camera bodies alone with no lenses or as complete kits with a cheap lens,
camera strap and perhaps other accessories included. Such kits are usually aggressively priced, and most consumers go for them since they’re convenient and the
supplied lenses are so cheap. The included lenses are usually referred to as “kit lenses,” though they can also be purchased separately if you like.
Unfortunately, kit lenses for low-end cameras are optimized for cheapness, as noted above. They aren’t engineered to offer the best optical quality you can find. This
means they’re usually not terribly sharp and they also tend to produce somewhat low-contrast photos. Kit lenses are also considerably less rugged than more
expensive lenses. Finally they’re always very slow lenses and so are not much good in low-light situations. These drawbacks are also the case, to varying degrees, for
kit lenses made by every manufacturer, incidentally, not just Canon.
Of course, a cheap kit lens will take better photos than a lens you can’t afford and thus don’t have. Particularly if you avoid shooting wide open and use an aperture
setting like f/8 to maximize sharpness. Nonetheless, you don’t have to settle for poor quality if you check out the used market or if you’re willing to pay a little extra -
see the section after next for details.
Why are quality lenses so expensive?
Lenses are very complex and costly products to design and manufacture. Each component has to be built to incredibly tight tolerances and carefully assembled. The
extremely pure optical-grade glass used in making lenses is very expensive to produce. Expensive lenses don’t have the volume sales of cheap lenses, making them
more expensive still to produce profitably. So, unfortunately, when it comes to lenses you generally get what you pay for.
Lenses going for 200-300 US$ or € may seem very expensive to a novice, but they are in fact considered dirt cheap lenses by professionals. This isn’t snobby elitism
necessarily - it’s just how it is. Lenses with high optical quality usually cost a lot of money. Photography is, unfortunately, a fairly expensive endeavour.
What’s a good beginner lens?
This really depends on your photographic goals. Here are some possibilities to consider.
But before you rush out and buy a lens based on these suggestions I strongly recommend trying out the lenses you’re interested in before you buy. Most decent
stores won’t mind if you go in with your camera and roll of film or an empty memory card and take a few shots of the shop using a couple of lenses. (be sure to use a
tripod or rest the camera on a sturdy surface and use identical settings for each lens) They might grumble a bit, but how else can you decide whether a given lens is
good for you? Certainly you don’t want to be trusting the advice of random people on the Internet!
Cheap prime lens.
If your primary objective is to learn more about basic photography skills and take photos of reasonable quality then your first lens should probably be a Canon 50mm
1.8 lens. This is a very fast fixed focal length lens. But since it’s technically easy to build a 50mm lens, it’s also astoundingly cheap. New Canon 50mm 1.8 mark II
lenses can be bought for as little as $75 US.
Such a lens, while cheap, takes sharp clear photos and can be used in extremely dim environments without the harsh light of a flash because it’s so fast. So the photos
you take with it will look better than those from a typical point and shoot both because they’re sharp and because you’re not bathing your photos in ugly glaring light
from a camera’s built-in flash. Natural light photographs almost always look better than on-camera flash.
Of course, since it’s a prime lens you will have to walk around more to get a lot of shots framed right. And some wide-angle or telephoto-type shots you won’t be able
to get at all, so those are the obvious disadvantages.
Note that Canon have made two versions of the 50mm 1.8 lens. The older lens has no Roman numeral designation and has a metal mount, a distance scale and an
optional clip-on hood. The mark II version has a plastic mount, no distance scale and a clumsy screw-on optional hood. If you can find an original lens it’s probably
worth going for - it costs as much used as the mark II does new, but is of slightly tougher build quality. Optically the two lenses are basically identical. Canon also sell
the 50mm 1.4 USM, which is optically a bit faster and uses a USM drive with FTM, but it costs considerably more than the 50mm 1.8.
However, if you use a digital camera with a cropped sensor (basically any EOS digital camera except for a few top models) then the 50mm might be a less useful
choice, since it essentially behaves like a longer telephoto on such models, and won’t let you get in much of a scene. In such cases a 28mm 2.8 might be a better
option.
Cheap zoom lens.
If you value convenience and image quality is not a priority then an inexpensive zoom lens, such as the kit lenses sold with consumer-level cameras, is fine. However I
don’t recommend most of these lenses (the “cheapies” in category 1 above) to anyone who’s at all interested in photographic image quality. The one exception is
probably the EF-S 18-55 kit lens included with the EOS 300/350/400 and Digital Rebel series cameras. This lens, while incredibly cheap, is actually not too bad if you
factor in the low cost. Especially if you stop down to f/8 or so when using it.
So what if you’re on a budget but really want the convenience of a zoom? Well, you could pick up a used zoom lens of an older generation, many of which have quite
decent optics for the price. For example, you could buy a used metal lens mount 28-70 3.5-4.5 II for nearly the same price as a new 28-80 all-plastic cheapie. If you
want a lens with silent-focussing USM you could consider the metal lens mount 28-80 3.5-5.6 USM (not one of the later plastic lens mount models with Roman
numerals), which has similar build quality to the 28-105 3.5-4.5 USM. Two other reasonable but discontinued lenses available inexpensively on the used market
include the 35-135 4.0-5.6 USM and the older 35-105 3.5-4.5. The main drawback is that these lenses aren’t really wide enough to be useful on cropped digital SLRs.
In short, you don’t have to put up with shopping mall quality just because you’re on a tight budget so long as you’re willing to consider used lenses.
Mid-priced zoom lens.
If you have a slightly larger budget, a mid-priced zoom (category 2) is worth considering. For example, two popular Canon zoom lenses are the 28-105 3.5-4.5 USM
and the 24-85 3.5-4.5 USM. Both are reasonably sturdy lenses with decent though not outstanding optical quality. They feature fast and silent ring USM autofocus
motors. They’re more expensive and heavier than cheap zooms, but most people find the tradeoff worth it.
Of the two lenses the former has a bit more reach and so is good for isolating objects or for doing simple portrait work. The latter has less reach but is considerably
wider (there’s a surprisingly big difference in coverage area between a 24mm lens and a 28mm lens) and so is popular for travel photos. The 24-85 is also a good
match for those digital cameras with less than full frame image sensors, such as the 300D/Digital Rebel/Kiss Digital or 10D.
If you’re interested in the 28-105 3.5-4.5 USM see the important note below about its similarly-named low-cost cousin.
What are some popular Canon EF and EF-S lenses?
Here are a number of popular Canon EF and EF-S lenses you might come across.
EF 16-35 2.8L USM and EF 17-35 2.8L USM.
Professional-quality new and old fast wide-angle zoom lenses, used by many photojournalists. Expensive.
EF 17-40 4L USM.
Affordable and optically slower version of the above, popular with advanced amateurs.
EF-S 18-55 3.5-5.6.
Pretty well every 300D/Digital Rebel, 350D/Rebel XT and 400D/Rebel XTi owner out there has one of these, since they’re bundled with most consumer Canon digital
SLRs sold. Image quality is OK considering the rock-bottom price.
EF-S 17-85mm 4-5.6 IS USM.
Very popular with users of Canon’s subframe D-SLRs, this lens combines decent image quality with a useful focal length range and has image stabilizing to boot.
EF 28mm 2.8.
Inexpensive lightweight wide-angle lens, suitable for landscapes and so on.
EF 50mm 1.8 and EF 50mm 1.8 II.
Super-cheap lightweight fast lenses, ideal for beginners and advanced amateurs. Take surprisingly sharp pictures for the price.
EF 50mm 1.4 USM.
Versatile standard lenses, useful in low light. These lenses contain micromotor USM mechanisms that unusually support full-time manual focussing.
EF 24-70 2.8L USM and EF 28-70 2.8L USM.
Large, heavy black L series lenses, noted for their high quality. Expensive and popular with wedding photographers.
EF 24-105 4L IS USM.
Very popular and quite expensive L-series image-stabilized walkaround lens.
EF 28-70 3.5-4.5 II.
Cheap older lenses with a reputation for decent optical quality despite the really low price. Rotating recessed end makes filter use awkward, however.
EF 28-80 3.5-5.6 II-V, 28-90 4-5.6.
Extremely cheap Canon lenses, supplied with many low-end camera bodies as kit lenses. Lousy optics.
EF 24-85 3.5-4.5 USM, 28-105 3.5-4.5 USM and EF 28-105 3.5-4.5 USM II.
Medium-sized, medium-priced and medium-speed lenses popular with many amateur photographers. The 24-85 is particularly popular with APS and subframe digital
EOS users owing to its wider short end. Do not confuse the 28-105 3.5-4.5 lenses with their cheaper and slower 4-5.6 cousins.
EF 28-135 3.5-5.6 IS USM.
Popular and versatile midrange lenses equipped with image stabilization for low-light shooting.
EF 85mm 1.8 USM.
Sharp and relatively inexpensive prime lenses, ideally suited for portraiture.
EF 100mm 2.8 Macro and EF 100mm 2.8 Macro USM.
True macro lenses capable of 1:1 closeup photography, yet equally useful as portrait lenses.
EF 70-200 2.8L USM and EF 70-200 2.8L IS USM.
Heavy white L series lenses, favoured by a lot of photojournalists. Expensive.
EF 70-200 4L USM.
Optically slower and less heavy siblings to the 2.8L. Considered a bargain for the price by many photographers, and popular with advanced amateurs.
EF 70-200 4L IS USM.
The image stabilized version of the 4L. Much more expensive, however.
EF 70-300mm 4-5.6 IS USM.
A popular lens for its compromise between size, convenience and image quality. Much sharper than its 75-300 predecessors, and image stabilization is a big plus. Not
to be confused with the DO (diffractive optics) lens, which is extremely expensive.
EF 75-300 4-5.6.
Commonly available cheapie-series telephoto lenses (see below). Ubiquitous owing to the low price, but optically poor.
EF 1200mm 5.6L USM.
Okay, so these gigantic and insanely expensive telephoto lenses aren’t popular as such, but always feature prominently in Canon’s lens advertising. Canon will gladly
custom-build one for you, given a prepaid order. I think they run for roughly the cost of a luxury automobile.
Frankly if you need this sort of focal length you’re better off with the 600mm 4L IS USM and a 2x teleconverter, though admittedly you’ll need an EOS 1V, 1D, 1Ds
or 3 to autofocus with it.
Should I buy a non-Canon (third party) lens?
Despite Canon’s vigorous advertising campaign against third-party lenses a lot of people happily use lenses made by Tamron, Tokina and Sigma (and lenses with
other brandnames but probably built by one of those three). And there’s one really good reason for this - the third party lenses are almost always much much cheaper
than equivalent offerings from Canon.
So. Should you buy a third party lens? It’s not a simple yes/no issue, so here are some points to consider.
• Price savings of third party products can be considerable, particularly if you’re looking to get a faster, higher-quality zoom lens.
• Remember that the cheapest lenses are optimized for price, not for optical quality. And the profit margins for cheap products tend to be very thin. The
price differential between Canon and third party isn’t huge when it comes to super-cheap lenses, so I don’t know if third party lenses are such a great idea in this
case.
• Third party makers produce lenses in a variety of market categories. Conventional wisdom is that if you’re considering third party at all you should
consider the higher end of their product line, not the lower end for the reason above.
• On the whole, Canon lenses seem to hold up their used value more than third party. If you intend to resell the lens anytime soon this can be a
consideration.
• Camera salespeople seem very eager to push third party lenses, so it’s likely that they receive bigger kickbacks from the manufacturers in return. Don’t
let yourself be swayed by an eager salesperson - he or she probably isn’t trying to convince you to buy something for your benefit.
• Buying Canon is pretty well a guarantee that your lens will work with any Canon EOS camera. However Tamron also have an excellent compatibility
record with EOS cameras. Always test with your camera first, but be aware that the lens may not necessarily work with future EOS cameras.
• Some older Sigma lenses do not work correctly with the latest EOS cameras. They fit the camera but don’t have compatible electronics, so the camera
tends to lock up when you try to shoot. If you have such a lens you’ll need to contact the manufacturer to see if they can provide a free repair to the problem. The
lenses don’t damage the camera - they just cause a temporary lockup that’s quickly cured by turning off the camera and turning it back on again.
• Build quality of older Sigma products is notoriously inconsistent. A quick search of the Web reveals countless complaints from unhappy Sigma lens owners.
Newer Sigma lenses seem to be a bit sturdier, judging by anecdotal evidence.
• Many of Tokina’s lenses have heavy metal lens barrels, which take a lot of abuse but are a drag when hiking.
• Canon offer many lenses with USM and full-time manual. Most third party lenses don’t have these features.
• There are some operational differences. For instance, some third party lenses have focus or zoom rings which rotate in the opposite direction from the
usual Canon direction.
• It’s difficult finding useful comparative data. You can look up the MTF scores on sites such as Photodo, which is a useful guideline, but the only way to
compare lenses properly is to test them yourself to see if they meet your needs. Asking, “Is the Tokina XYZ 2.8 lens better than the Canon XYZ 2.8 lens?” rarely
yields helpful answers, because most people don’t buy both lenses and try them out.
• Some specific third party lenses are better known than others. For example, Tamron’s 90mm macro lens has a reputation for excellent image quality at a
price considerably less than Canon’s 100mm macro. Sigma sell an 8mm fisheye which Canon do not make.
• But the biggest deciding factor is, as always, money. Only you can decide what’s your priority - low initial purchase price, mechanical reliability,
compatibility, user interface or optical quality.
Types of lenses.
Why doesn’t my camera have a motorized zoom lens with wide/tele buttons?
Because it’s not a point and shoot. Such motorized lenses are fine for simple tiny consumer-oriented cameras, but SLRs with interchangeable lenses are meant for a
different market.
All Canon EF zoom lenses but one are manual zooms. That is to say you adjust the focal length either by turning a ring (two touch) or sliding the lens in and out
(push-pull). And most people find that adjusting the zoom setting on such lenses is much faster and more precise than a slow and cumbersome motorized point and
shoot zoom lens.
Note that Canon did briefly sell a motorized zoom lens for EOS cameras a while back, presumably as a sort of experiment. That lens, the Canon EF 35-80 4-5.6 PZ
(Power Zoom), was an all-plastic cheapie with fairly low optical quality. The lens barrel had two pushbuttons that let you adjust the zoom position.
What’s the difference between all the Canon 28-105mm lenses?
Canon sell and have sold a number of different lenses which use the 28-105mm focal range.
28-105mm 3.5-4.5 USM, flower icon.
This is the first version of this popular lens, released in the early 1990s. It’s a midrange consumer zoom with decent optics and a fast and silent ring USM motor with
FTM. The mark I version with a flower icon on its lens barrel apparently had a 5-blade aperture diaphragm. Marked with a striped gold line since it’s a USM lens,
and has a metal lens mount. Discontinued.
28-105mm 3.5-4.5 USM, “MACRO” icon.
This is the second version of the lens, though it was never officially identified as such - it’s still considered to be a mark I. It’s identical to the first version but it has
the word MACRO printed on the lens barrel in lieu of the flower (closeup) icon. Internally, however, it has a 7-blade aperture diaphragm, which in theory offers
slightly better bokeh, or out-of-focus blurring. Marked with a striped gold line since it’s a USM lens, and has a metal lens mount. Discontinued.
28-105mm 3.5-4.5 USM II.
This is the official second version of the lens, as indicated by the II symbol. According to Canon the original 28-105 and the mark II versions have identical optics, but
the mark II version has slightly different external styling, including an allegedly slightly tougher design. According to Canon Malaysia an internal component used in
the zoom mechanism has been updated to metal from plastic. Marked with a striped gold line since it’s a USM lens, and has a metal lens mount. Discontinued.
28-105mm 4-5.6 USM.
This lens is a cheapie lens, released in 2002. It is a completely different and very much inferior lens from all the ones listed above. It’s almost entirely made of plastic
(including the lens mount) and has vastly worse optics than the faster lenses. It can easily be identified by the silver (chrome) ring around the end of the barrel.
Interestingly, while it uses a micromotor USM autofocus system it nonetheless supports full-time manual, according to Canon’s literature. It’s a lens intended for
consumers and does not fit the same position in the lineup as the 28-105 3.5-4.5 USM II.
In short, be very careful when shopping for a 28-105 lens. You don’t want to buy a lens thinking it’s the popular midrange lens only to end up with the bottom of the
line cheapie instead. Always double-check the listed aperture range before buying.
Should I buy the Canon 28-200 or the Tamron 28-200 or the Sigma 28-300 (or some other lens with a big focal range)?
A popular question back in the late 90s, when such lenses were heavily marketed as the ultimate in consumer convenience since they cover such a huge focal length
range. Sadly, the lenses tend to be fairly big and heavy, as consumer lenses go. And most importantly, the optical quality of these lenses leaves a lot to be desired.
It’s very difficult to build optically sharp zoom lenses, particularly those with a really wide zoom range like these ones. The lenses are pretty slow, with small
maximum apertures. They also tend to have a lot of distortion, which makes squares and rectangles in photos appear like they’re bulging in or out slightly - bad for
photos of buildings.
If you only take 4"x6" snapshots then these drawbacks are probably fine, but if you ever want to make enlargements beyond that you may find that your photos look
disappointingly soft - not very sharply focussed. Since they’re optically so slow you’ll probably also find that any telephoto photos you take will be badly blurred
unless you use a tripod or flash. Finally, using long telephoto lenses requires a certain degree of technique and experience since the focal lengths are so long. You
can’t easily handhold a slow 300mm lens, for example. Doing so, particularly without high-powered flash, is a surefire recipe for disappointingly blurry photos. And
Sigma has regrettably a long history of older lenses turning out to be incompatible with later EOS cameras.
As a beginner you’re probably best off getting one or two lenses of a more modest focal length range, no matter what nonsense the salesperson in your camera shop
may say about you never needing to buy another lens again. In short, consumer-level 28-200 or 28-300 lenses always suffer from tremendous optical compromises;
compromises which render them of limited value, especially at the long (200-300mm) end.
There are really only two lenses with a huge focal length range that are generally accepted as possessing decent optical quality - Canon’s 35-350 3.5-5.6L and
Canon’s 28-300 3.5-5.6L IS. However both are gigantic and expensive lenses not intended for beginners.
What affordable Canon long telephotos are there?
Canon make telephoto zooms which fall mostly into two basic categories - very cheap slow lenses with mediocre optical quality and very expensive fast lenses with
fabulous optical quality. There are few intermediate choices, though the 70-300 4.5-5.6 IS USM is one to consider. Canon have also never built any affordable long EF
telephoto prime lenses - all EF telephoto primes longer than 135mm are L series lenses.
There are a number of Canon zoom lenses in the 75mm to 300mm range, however. Here’s a bit of basic information about some of them.
75-300 4-5.6
75-300 4-5.6 USM
75-300 4-5.6 II
75-300 4-5.6 II USM
75-300 4-5.6 III
75-300 4-5.6 III USM
Canon sell and have sold quite a few different lenses with focal lengths from 75mm to 300mm. All apparently use the same optics - they just have different cosmetic
styling of the lens barrel (the mark III version, for example, has a silver ring on the end to impress novice camera buyers) and different autofocus motors. They’re
very inexpensive lenses as telephoto zooms go, but offer fairly mediocre optical quality. At the short (75mm) end they’re not too bad but at 200-300mm they tend to
get very soft (slightly blurry). You really need to stop them down to f/8 or f/11 or so for okay optical quality, which of course requires longer shutter speeds.
The 75-300 USM models all have micromotor USM autofocus mechanism which do not support full-time manual (FTM). All other versions of this lens use slow and
noisy micromotor or DC motor drives. These lenses, while in the “cheapie” category of Canon lenses, have metal lens mounts. They do not, however, have distance
scales. All versions of this lens have rotating ends when focussing, which makes using a polarizing filter rather inconvenient.
75-300 4-5.6 IS USM
One notable lens in the 75-300 series is the IS model, which offers image stabilization for improved shooting at lower shutter speeds. It was the first IS lens offered by
Canon, but the lens sadly has the same unremarkable optics as the other 75-300 lenses.
70-300 4.5-5.6 IS USM
Do not confuse this lens with the cheaper 75-300 crowd or the more expensive DO lens with almost the same name. This lens combines decent optics with image
stabilizing and is an excellent compromise for the advanced amateur. It’s not quite as sharp as the 100-300 5.6L, but IS makes it a lot more convenient since you end
up with a much higher percentage of keepers when used off-tripod.
70-300 4.5-5.6 DO IS USM
This lens is particularly unusual in that it’s the first zoom lens to use diffractive (DO) lens elements. This Canon technology allows for smaller and lighter lenses. The
70-300 DO is considerably shorter than its 75-300 siblings, and has image stabilization (IS) technology to boot. It isn’t cheap, however. Do not confuse it with its
non-DO sibling.
90-300 4-5.6 USM
I really don’t see the point of this lens. It appears to be pretty well the same as all the cheap 75-300 lenses, only its short end starts at 90mm. It’s USM but only
micromotor USM and thus has no FTM.
100-300 4.5-5.6 USM
This lens is, in terms of build quality and physical appearance, the telephoto zoom counterpart of the 28-105 3.5-4.5 USM and the 24-85 3.5-4.5 USM. It has
reasonably solid construction, a fast and silent ring USM autofocus drive which supports full-time manual (FTM), does not having a rotating end and has a distance
scale. Optically the 100-300 USM I had was very slightly sharper than the 75-300 at the long end, but many people report that there’s really no difference between
their samples of the lenses. Essentially the 100-300 USM gives you improved focussing speed and a more convenient user interface compared to the 75-300s, but not
improved optics. You also lose 25mm and half a stop off the short end, for what it’s worth.
70-210/3.5-4.5 USM
The predecessor to the 100-300 4.5-5.6 USM. Very similar in size and construction, only with a focal range that’s shorter at each end. Offers similar optical quality.
100-300 5.6L
An older and now discontinued lens, the 100-300 5.6L is an interesting lens in that, while it’s technically an L series lens with fluorite and UD lens elements, it doesn’t
have the tough build quality of a typical L series lens sold today. It uses a slow and noisy AFD autofocus motor and has an awkward (low-profile) and fiddly (hard to
slide) MF/AF switch. The manual focus ring is also rather gritty to turn. However, it does offer considerably improved optical quality over the 75-300 series and the
100-300 USM. It's also sharper than the 70-300 IS USM. So if you can deal with the slow optical speed (maximum aperture of only 5.6) and the horribly sluggish
autofocus motor it’s well worth looking into if you’re on a tight budget.
50-200/3.5-4.5 L
Similar to the 100-300 5.6L, in that it’s a first generation EF-mount L series lens. It has the optics of a modern L series lens - but not the build quality - and has a
push-pull zoom design. The 50-200 isn’t a bad lens, but for some reason holds its used market value rather well. Personally I think the 70-200 4L USM is a better
deal. It’s typically not much more money but gives you better build quality and silent focussing USM.
70-200 4L USM
This lens, the smaller and cheaper sibling of the impressive 70-200 2.8L USM professional lens, is considered a bargain by many EOS users. It costs three times as
much as the cheapie lenses but it’s sturdy, focusses quickly with a ring USM system with FTM and, most importantly, it has great optical quality. It’s bigger and
heavier than the consumer lenses, but if you want something good but can’t afford the 2.8L, consider this lens. It doesn’t use a huge 77mm filter like the 2.8L - it uses
a 67mm filter like the 24-85 3.5-4.5 USM. This is a little unfortunate, has hardly any other Canon lenses have 67mm filters.
70-200 4L IS USM
The image stabilized sibling to the 4L. Visually almost identical, down to the 67mm filter, but much much more expensive than its non-L counterpart. According to
some reviewers, one of the sharpest Canon lenses in its whole zoom lens range.
80-200 4.5-5.6
80-200 4.5-5.6 USM
80-200 4.5-5.6 II
Plastic cheapies, basically analogous to the 28-80 plastic cheapies. They are very lightweight and portable, though. If you want something really inexpensive and
never enlarge your photos past postcard size then they’re fine.
100-300 5.6
With pretty well identical build quality to the 100-300 5.6L, this older lens has all the disadvantages of the 5.6L without the sharp optical quality of the L lens.
I want to take photos of wild birds. What lens do I need?
You probably won’t want to hear this answer, but nature photography of small and fast-moving wild animals is a difficult field and basically requires really expensive
lenses. 500mm and 600mm lenses are commonly used by bird photographers - your typical 100-300mm zoom lens is just not long enough for great photos. And lenses
longer than 300mm are both incredibly expensive and really heavy.
So the harsh reality is while you may be able to get nice snapshots of fairly tame birds with a 100-300mm lens you won’t be able to get those amazing wildlife book or
calendar shots - small birds filling the entire frame - with one. You can always use your lens at 300mm and then crop off the edges of the picture, but then picture
quality will suffer.
If you really want to do this type of photography on a tight budget you might want to consider buying used manual focus gear. You can find really quite decent used
high-end manual focus telephotos quite inexpensively compared to their autofocus counterparts.
I want to do sports photography. What lens do I need?
Unfortunately, this answer is going to be somewhat like the previous one. The challenges of sports and other action photography are twofold. First, by its very nature,
sports photography tends to involve rapid motion - fast-moving players or cars or whatever. Second, usually there’s some distance between the action and the camera.
Solving the first problem requires lenses which can let in plenty of light, the use of flash or faster film or high ISO settings on a digital camera. Each of these solutions
has drawbacks, however. Fast lenses are large, heavy and expensive. Fast film or high ISO settings result in higher grain or noise and thus lower picture quality. And
flash may be inadequate to illuminate the subject effectively, particularly if the subject is some distance away.
Solving the second problem basically requires the use of long telephoto lenses. However, most affordable autofocus telephoto lenses are very slow - they don’t let in
much light. So this amplifies the first problem.
Now obviously there are some cases where these two issues aren’t a massive problem. For example, perhaps you’re shooting a basketball game and you’re in the
front row. Basketball courts are of a modest size and so you could probably do okay with flash (assuming you’re allowed to use flash - some places won’t let you as it
can temporarily blind or distract the players) and you won’t need an incredibly long lens accordingly. Such a situation is a little less challenging than shooting hockey
on a big, poorly lit, rink.
Nonetheless, pro photographers rely on fast lenses, and this is the primary stumbling block for amateur photographers on a budget. Fast telephoto lenses, especially
fast telephoto zooms, are really expensive. And there’s not much you can do to work around that fact without a lot of compromises. To cover these points further:
Fast lens. Get the fastest (largest aperture) lens you can afford. A 70-200 2.8 lens is great for basketball, for example. A 75-300 4-5.6 is probably not, since even
shooting wide open means you’ll have slow shutter speeds, which will result in unwanted motion blur.
Telephoto lens. You’ll need a long telephoto zoom unless you’re planning on shooting very close to your subjects. For example, you won’t need a long lens to shoot
skateboarders in an urban setting, but you will if you’re covering a football game.
Cropping. You can always make up for a long lens to a certain extent by cropping the picture - trimming off the edges. The problem with this is that enlarging the
picture also enlarges the grain in the case of film and lowers the apparent resolution in the case of digital.
Image stabilization. Useful for reducing blurring caused by camera motion, but of no value whatsoever in freezing subject motion.
Flash. Useful both for illuminating the subject and freezing subject motion. Not every venue permits flash usage, however.
Film/ISO speed. Fast film or high ISO settings are needed to keep shutter speeds to a minimum. Once again this involves tradeoffs with picture quality.
Camera with fast focus. A fast pro camera (such as the EOS 1 series) can lock focus surely and accurately and has minimum lag time when the shutter release is
pressed. A consumer camera is not going to be as surefooted and decisive, and will make it harder to nail the perfect shot.
Fast lens motor. A Canon ring USM lens can autofocus rapidly, whereas a Canon AFD (arc form drive) lens cannot. A lens with a rapid motor frequently makes the
difference between achieving a shot and getting nothing.
To summarize - if you plan on putting a 75-300 4-5.6 consumer lens onto your camera, don’t expect photos like those which grace sports magazines. This isn’t to say
that you can’t get satisfactory photographs with such equipment, just that it’s challenging to do so. It takes a lot of skill, experience and luck to come up with
consistently good results. And you should be operating on the expectation that you will face problems with blurring of the subject and general low sharpness and low
contrast if you use an affordable consumer telephoto zoom lens.
What about mirror lenses? I can get a really cheap telephoto that way!
Some third-party lens makers sell mirror or, as they’re more accurately known, catadioptric lenses. Such lenses use a pair of mirrors to fold the light path in half, in
addition to containing regular glass elements. The advantages are that mirror lenses can be made fairly cheaply and will also be shorter and lighter than all-glass
(refracting) lenses of the same focal length. And mirror lenses with focal lengths of 500mm to 1000mm are not uncommon. Russian makers produce a lot of these
lenses.
Unfortunately mirror lenses have a number of drawbacks. First of all, they’re manual-focus only. Second, they are optically really slow lenses - usually around f/8 or
so. Third, they don’t have aperture diaphragms, so the only way to adjust the exposure is to adjust the shutter speed, the film speed/digital ISO or to put a neutral
density (darkening) filter on the lens. Fourth, the smaller of the two internal mirrors blocks the light path somewhat, resulting in rings or doughnuts appearing around
bright highlights in out of focus areas. This effect, a form of bokeh, can be visually very distracting. And fifth, they tend optically not to be of the highest quality -
you’re not going to get National Geographic-quality bird photos using them.
So, while such lenses are attractive if you’re on a budget, they do have many limitations associated with them. You’re probably better off buying a used manual-focus
refracting (non-mirror) lens and adapting it to your camera, or buying a manual-focus body. As noted above, photography can be a really expensive endeavour.
What is a macro lens? My lens has MACRO written on it.
Macro photography is the somewhat confusing name for closeup photography. Just as the human eye can only focus up to a certain distance (a distance which moves
alarmingly further away with age), not all lenses can focus as closely as others. Most lenses are designed to focus up to a metre or two with long telephoto lenses
having much longer minimum focussing distances than that.
Now this obviously isn’t going to help you if you want to take a super closeup of a small flower - you need a much shorter minimum focussing distance. Basically you
want to be able to fill the frame with your small subject. And another concept comes in - the magnification factor. Traditionally, true macro photography refers to 1:1
photography and smaller. In other words, a lens with 1:1 magnification is able to image an area as small as the exact size of the image format in question. In the case
of 35mm film this means an area of 24x36mm in size. Sometimes magnification is written as a decimal factor, such as 0.25x or 1.0x.
Unfortunately, lens manufacturers tend to throw around the word “macro” with cheerful abandon as a marketing gimmick. The fact a lens has MACRO printed on it
basically means nothing, and you have to look closely at the lens specs. If a lens can do 1:1 or 1:2 photography then it’s a real macro lens, optimized for closeup
photography. It may also be designed with a flat field so it can be used to take photographs of flat objects like stamps without focus problems. Lenses that can only
reach 1:4 or whatever can’t take really close-up pictures.
True macro lenses are generally of much higher optical quality than ordinary lenses and usually cost more. They are also usually optimized to take photographs of
small flat objects with even focus across the surface - flat field. They’re still a good buy if you don’t do a lot of macro photography, however. You can always use them
for regular photography as well - they just have the bonus that they can focus much closer than ordinary lenses can.
What is a portrait lens?
Obviously any lens can be used to take a portrait of someone. However, the results can be very different depending on its focal length.
The distance required between you and your subject, when you take a head and shoulders portrait, depends on the focal length of the lens. If you have a wide angle
lens then you need to stand very close to them in order to have their head and shoulders fill the frame. But if you have a telephoto lens then you need to stand a fair
distance away from them for the same effect.
This distance results in a change in perspective. Try this experiment with someone in real life without using a camera. If you stand really close to the person and look
at their face you’ll notice that this position tends to emphasize their nose and make their forehead look like it’s sort of sloping away. But if you’re further away from
them then their face tends to look flatter. And generally speaking people find that a slightly flatter perspective on a face is usually a bit more flattering in general.
Portraits taken with wide-angle lenses can, in fact, have a rather comical or grotesque effect.
So generally photographers like to use lenses of about 85mm to 135mm in length when taking head and shoulders portraits, depending on the look they’re trying to
achieve. Some fashion photographers even use 200mm and 300mm telephotos for a particularly flat effect. You can take photos of people with 50mm and shorter
lenses, but these lenses tend to distort the face somewhat. Such shorter focal lengths are, however, perfectly fine for waist-up or full body shots.
Canon make a number of of popular lenses used for portrait photography. Two of the more affordable ones include the compact and sharp 85mm 1.8 and the 135mm
2.8 SF which has a “soft focus” feature which allows you to introduce image-softening at will.
Finally, note that the lens focal lengths I list here are for 35mm film or full-frame EOS SLR. If you’re using a camera with a smaller image area - digital or APS - then
the ideal focal lengths for portraits are going to be shorter. For example, a 50mm lens is generally considered a bit short for most portraiture with 35mm film, but
when mounted on an EOS 10D digital camera it takes photos much like those taken with an 80mm lens on a 35mm film camera.
What is a fisheye lens?
Most lenses are “rectilinear,” which means they’re designed to project an image onto a flat surface (the film or the image sensor) and render straight parallel lines as
straight parallel lines. This is actually a complicated optical trick, since a simple lens really wants to project an image onto a spherical surface (such as the interior of
the human eyeball). It also becomes increasingly complicated to do as the field of view of the lens becomes larger, as with wide-angle lenses - one reason why really
wide angle lenses are so expensive.
This type of projection onto a flat field is something that different lenses do to varying degrees of success. High quality lenses, particularly those intended for use for
macro or architectural photography, do a pretty good job. But cheaper lenses will compromise on this slightly and will either barrel or pincushion somewhat. That is to
say, a photograph of a square object may appear to be either bulging outwards or squashed inwards, because parallel lines are being portrayed as curved. In fact,
nearly all cheap lenses tend to have barrel distortion - it’s just that people usually don’t realize it because they rarely take photos of square or rectangular objects.
A fisheye lens is a wide angle lens where no effort has been taken to render parallel lines as parallel. Instead, only lines which pass through the centre of the frame
are straight. All other lines appear as curves, becoming increasingly curved as you near the edge of the frame. This line curvature has the effect of making near
objects seem closer and more distant objects seem further off, as they fall away. If you’ve ever looked through the glass peephole viewers in a door then you know
the effect.
Sometimes people call rectilinear lenses “corrected” and fisheye lenses “distorting,” but I don’t think that’s very useful or accurate. Rectilinear lenses aren’t
necessarily correct - a wide-angle lens has extreme distortion and stretching towards the edges to make the lines straight. That being said, the fisheye effect is very
pronounced and extreme, and does render scenes in a characteristic fashion. Portrait photographs of people taken with fisheyes, for example, have cartoon-like
bulging noses and so on.
Fisheye lenses are useful for three basic things. First, it’s a lot easier to make a super wide angle fisheye than it is a super wide angle rectilinear lens, so a fisheye
lens is going to be cheaper than its rectilinear equivalent. Second, and this is how fisheyes came about, it’s possible to build a fisheye lens which covers a full 180°
field of view, which is very handy for scientific photography, particularly of the sky. And third, bulgy wide angle effects are fun for taking crazy trippy photographs.
There are two basic types of fisheye lenses. Circular or 180° fisheyes cover a full (or nearly full in most cases) 180 degree field of view across the narrower side of
the image rectangle. These lenses make photos that look like bulging circular balls on a black background. The other type are sometimes called full frame or semi
fisheyes and basically offer a cropped field of vision so you don’t get the black areas at the corner of the picture. As a result they only cover 180 degrees of view on
the diagonal.
On 35mm cameras, full frame fisheyes usually have a focal length of 8mm, and semi-fisheyes have a focal length of 15mm or 16mm. In near-circular lenses, Japanese
maker Sigma sell an 8mm autofocus fisheye for use with EOS cameras, and Belarus maker Peleng sell an 8mm manual-focus fisheye that can be adapted to EOS
cameras. In full frame fisheyes, Canon sell a 15mm autofocus fisheye for EOS, and Russian maker Zenitar sell a 16mm manual-focus fisheye lens which can be
adapted. There are also popular screw-on adapters that convert ordinary lenses into fake fisheye lenses. Such adapters are virtually all of extremely low quality, but
are definitely fun to play with.
A lot of photographers turn up their noses and dismiss fisheyes altogether as gimmicky remnants of the 1970s. Personally I think fisheye distortion can yield
interesting effects if used occasionally, but it’s obviously not something you’re likely to use every day. In nature or underwater photography, where there are few
straight lines, fisheyes can be a useful tool as well.
Lens features.
What is the difference between two-touch zoom and push-pull zoom?
There are two basic ways to adjust the focal length of a zoom lens. Some zoom lenses have a zoom ring as well as a focus ring and so are called two-touch. Rotating
the zoom ring adjusts the focal length. Other lenses slide in and out like a trombone or telescope; the so-called push-pull design.
The push-pull design is more vulnerable to zoom creep than two-touch. This is the problem of the zoom accidentally adjusting focal length (sliding) when tilted up or
down because the friction of the push-pull system isn’t enough to counteract the weight of the lens. Push-pulls also tend to suck in a lot of air and therefore dust into
the lens when adjusted. However, push-pull lenses can be operated more rapidly, if usually a bit less accurately, than two-touch zooms.
Why are some Canon lenses painted white or silver?
Nearly all large telephoto L series lenses have barrels constructed from solid metal and painted off-white, rather than black plastic or black-painted metal. Canon say
they do this since white surfaces absorb less heat than black when used out in the sun, and fluorite crystal lens elements are sensitive to heat - they can expand and
contract, altering their optical properties. Of course, the fact that a white-painted Canon lens stands out in the crowd is probably part of the reason as well. Look at
any major sports event and you’ll see rows of hefty white lenses. Though to confuse matters Nikon have also begun to sell some lenses in optional white paint.
A few lenses intended to be sold as kit lenses with silver-painted camera bodies have also been available with silver-painted plastic barrels. These include the 35-135
4-5.6 USM (to match the silver-painted commemorative edition of the EOS 10/10s which was released to mark the sale of 60 million Canon cameras), the 24-85
3.5-4.5 USM (to match the APS IX camera) and the 28-90 4-5.6 USM II (to match the Rebel Ti/EOS 300V/Kiss 5). The silver paint on these midrange and low end
lenses is purely for cosmetic reasons.
What is a tripod mount on a lens for?
Normally you put a camera onto a tripod by attaching the camera body right to the tripod head itself. But if you have a really heavy lens this is a bad idea. Large
lenses can often weigh far more than the heaviest SLR cameras. So the right way to do it is to attach the lens to the tripod head via a tripod mount. The camera then
sort of hangs off the back of the lens unsupported, but this isn’t a problem - lens mounts are designed to handle that kind of weight easily.
Lens tripod mounts or collars are mounting rings with built-in clamps. These rings make it easy to rotate the camera from portrait (vertical) to landscape (horizontal)
position. If the maker of your lens sell a tripod mount for the lens then it’s probably wise to get one.
What is a distance or depth of field scale?
Most Canon EF midrange and better lenses have distance scales - clear rectangular plastic windows set into the lens barrel. A series of numbers can be seen through
this window indicating the distance, in both metres and feet, from the lens to the point in focus. Inexpensive consumer lenses generally do not have distance scales.
Canon EF prime lenses also have simple depth of field scales marked on the barrel below the window. These marks indicate the acceptable depth of field distances
from the current focus distance, usually for a small number of apertures - f/11 and f/22, say, or f/5.6, f/11 and f/16. Canon EF zoom lenses, however, do not have any
depth of field scales because of the complexity of indicating depth of field over varying focal lengths.
You’ll notice that there is usually a red dot on the distance scale window as well. This is used for determining the focus distance when using infrared film with an
infrared filter. Since infrared energy focusses at a different point from visible light this dot is a useful aid. However, if you’re using infrared film with an ordinary red
filter or no filter at all then you may not need to adjust focus using this dot, since much of your image is going to be visible light anyway. For more information please
consult my Infrared Myths document.
What is the issue with a rotating end of a lens?
Some lenses have an outer end which rotates when you adjust either the focus or the zoom setting or both. Others do not.
This matters a lot if you’re using a polarizing filter or a graduated neutral density (ND) filter, since the properties of the polarizer vary depending on its angle of
rotation and the graduation line runs across the filter in a straight line. It can be very annoying to set a filter to achieve the effect you want, touch up the focus, and
find that the polarizing or graduated ND effect has changed because the end of the lens has rotated.
Why does it matter how many blades the aperture diaphragm has?
The adjustable aperture diaphragm in most camera lenses consists of a number of flat wedge-shaped metal blades. As you adjust the lens aperture settings these
blades rotate in or out, and the aperture opening changes size in an iris-like fashion.
The shape of the hole made by this adjustable diaphragm depends on the number of blades and the shape of the blades. For example, if you have a 5 blade aperture
diaphragm then the aperture will be a pentagon in shape. An 8 blade aperture diaphragm will of course yield an octagon.
There are two areas in which this aperture shape affects the final image. First, the shape of lens flare on a photograph is typically governed by the shape of the
aperture. You may have seen photographs with pentagonal or hexagonal lens flare, for example, or star-shaped highlight areas in a photograph taken with a small
aperture setting. Second, it’s generally held that the closer the aperture is to a circle the smoother out of focus areas (bokeh) tends to be, though it isn’t the only
factor contributing to bokeh. Many lenses have at least 6 or 8 aperture blades, frequently with curved edges, to approximate a circular aperture opening for this
reason. Canon have in fact started billing some of their recent lenses as having “circular” apertures, indicating near-circular openings.
Which lenses are weather-resistant?
Most of Canon’s new professional (L series) lenses introduced since mid 1999 are equipped with gaskets and rings to keep out dust and moisture. They’re not
waterproof, by any means, so don’t go diving with them. But they’re much more resistant to inclement weather than Canon’s other products.
Of course, a weather-sealed lens isn’t much good unless you have a weather-sealed camera to match it. And at present only the top of the line EOS 1V, 1D, 1Ds 1D
mark II, 1Ds mark II and 1D mark IIN cameras (but not the 1, 1N or 3, which have lesser sealing systems) have the same level of weather sealing - gaskets and
rings around every opening, button and switch, in fact. You can use the sealed lenses with non-sealed cameras, of course, but the gasket around the lens mount will
still let in water unless mated to the gasket around a sealed camera. (this rubber ring around the lens mount is, incidentally, an easy way to tell if a lens is weather
sealed or not)
At time of writing the weather-resistant Canon lenses are:
16-35mm 2.8L USM
16-35mm 2.8L II USM
17-40mm 4L USM
24-70mm 2.8L USM
24-105mm 4L IS USM
70-200mm 2.8L IS USM
70-200mm 4L IS USM
28-300mm 3.5-5.6L IS USM
50mm 1.2L USM
85mm 1.2L II USM
300mm 2.8L IS USM
400mm 2.8L IS USM
400mm 4 DO IS USM
500mm 4L IS USM
600mm 4L IS USM
The mark II versions of Canon’s teleconverters, the Extender EF 1.4x II and Extender EF 2x II, also have weatherproofing. None of Canon’s more affordable lenses
or cameras have weather sealing. Note also that weather-resistant zoom lenses do not have sealed glass ends - you need to put a filter on these lenses to seal out the
far (non camera) end.
What is the close or minimum focus distance?
Just like a human eye, camera lenses have a near point at which they cannot focus anymore. This focus distance depends on the lens construction, but typically wide
angle lenses have nearer close focus distances than telephotos. Many macro lenses, of course, are optimized for near close focus distances.
If you’re a human you can adjust this close focus distance by moving the object you’re trying to focus on further away. Similarly you can add extension tubes to your
lens to move the lens further from the camera and thus bring the close focus distance closer. You will lose the ability to focus on infinity with such a tube, though.
Hey! I can turn the focus ring of my lens past the infinity mark! Why?
Your lens can go to infinity - and beyond! Yes, many lenses can be adjusted past the infinity marking on the lens barrel.
It’s not a problem. Such lenses are intentionally designed this way to allow the lens to compensate for the changes in optical characteristics that occur when the lens is
subjected to ambient temperature changes. (the focus of lenses can be affected by thermal expansion)
What does a lens hood do?
Aside from making the lens look longer and bigger and thus more impressive to non-photographers, lens hoods (sometimes called shades) serve two basic functions.
First, they help reduce the amount of stray light hitting the surface of the lens. This is a good thing, since non-image-forming light coming into the lens at an angle
results in lens flare. Lens flare can result in lower-contrast images or, in extreme cases like light from the sun, can result in big glowing blobs in the final photo.
Second, lens hoods serve as physical protection for the lens - the plastic or metal tube can absorb blows that might otherwise hit the glass itself.
Lens hoods come in a number of basic forms. The two types sold by Canon today are tube-shaped hoods and petal-shaped (notched) hoods, made of hard black
plastic. The petal-shaped type are sometimes called “perfect” lens hoods and shield the lens more effectively than simple tubes of the same weight. This is because
the notches are cut out to match the rectangular shape of the imaging area (think about it).
Some hoods clip onto the lens, some twist on bayonet-style and some screw onto the end. Some are lined with black light-absorbing flocking and some are not. You
can also buy flexible adjustable rubber hoods from third party makers, but Canon do not sell any such hoods themselves.
Unfortunately, lens hoods are hugely overpriced. Camera makers somehow feel justified in charging massive sums for simple moulded plastic tubes. Ah well.
How are lens hoods named?
Canon lens hoods are identified by a confusing and cryptical alphanumeric code. There is a system to the hood naming, though it’s only somewhat informative. Still, if
you understand how the hood naming works you can usually figure out which hoods can be interchanged with other lenses.
• The first letter in a hood name is E, indicating that the hood fits a Canon EF mount lens.
• The second letter is either W, S or T. W stands for Wide, S for Standard (probably) and T for Telephoto.
The letter refers to the type of lens to which the hood fits. W is for any lens wider than 50mm, S is for a 50mm lens (with a couple of odd exceptions) and T is for any
lens longer than 50mm.
• The two letters are then followed by a number which indicates the size of the hood mounting ring in millimetres. Some hoods fasten to the very end of the
lens barrel by means of a bayonet (rotating and locking) mount and others clip further down the barrel to a small ring by means of small spring-loaded plastic clips in
the hood. Generally newer lenses use the former style and older lenses the latter.
• The hood size is sometimes followed by a letter from A through D. This letter indicates the hood style, and unfortunately there’s no real way of knowing
what style fits what lens without looking it up, because the hood style appears to be chronological depending on when the lens was released and whether there
happened to be any lens hoods already in the lineup with otherwise identical specifications but with a different shape. There is no way to tell if the hood is a standard
tube or a petal shape (“perfect”) lens hood just by looking at this letter.
For example, the original EW-78 fits the 35-350 3.5-5.6L USM, the EW-78B fits the EF 28-135 3.5-5.6 IS USM, the EW-78C fits the EF 35 1.4L USM and the
EW-78D fits the EF 28-200 3.5-5.6.
• Finally, the hood name sometimes ends in a Roman numeral - typically either II or III. This indicates the hood version.
Generally speaking, mark II and III hoods are flocked on the interior with black anti-reflective material, like velvet. Hoods with no Roman numeral designation are
typically painted flat black, but since this depends in part on when the hood was released this is not a guarantee. Some mark II hoods also have slightly more
clearance around the end of the lens so that polarizing filters fit better if their predecessors didn’t.
Some hood naming examples:
ET-65 III
E indicates that the hood fits an EF mount lens.
T indicates that the hood fits a telephoto lens.
65 indicates that the hood mount is 65mm in diameter.
III indicates this is the third hood of the ET-65 series, and means in this case that the hood is flocked to reduce reflections.
This particular lens hood fits a number of Canon EF telephoto lenses - the 85 1.8 USM, the 100 2.0 USM, the 135 2.8 SF, the 70-210/3.5-4.5, the 75-300 4-5.6 and the
100-300 4.5-5.6 USM.
EW-78B
E indicates that the hood fits an EF mount lens.
W indicates that the hood is for a wide angle lens.
78 indicates that the hood mount is 78mm in diameter.
B indicates that it’s a hood of type B.
This particular hood fits the 28-135 3.5-5.6 IS USM.
ET-160
E indicates that the hood fits an EF mount lens.
T indicates that the hood fits a telephoto lens.
160 indicates that the hood mount is 160mm in diameter.
This gigantic hood fits the 600mm 4L USM IS.
Knowing this system you can figure a few things out. For example, the EW-65, ES-65 and ET-65 can all clip onto the same lenses - the only difference is the length.
The EW-65 is the shallowest lens and the ET-65 the deepest, so putting an ET-65 onto a 28mm 2.8 lens is a bad idea as you’ll get vignetting unless you have a
cropped image sensor on a digital camera. But you can put an EW-65 onto a 100-300 4.5-5.6 USM if you like. It won’t shield your lens as effectively as the longer
hood, but it’s better than nothing. Or if you can’t find the discontinued ES-65 you can always use the EW-65 instead.
General lens questions.
Is it okay to change lenses when there’s film in the camera?
Yes. A key advantage of a camera with interchangeable lenses is the ability for you to change lenses whenever you want. The camera body contains a shutter which
prevents light from hitting the surface of the film regardless of whether or not the lens is attached.
Of course, you should try not to change lenses when you’re outside in the pouring rain or in the middle of a sandstorm or whatever. And don’t poke your fingers into
the shutter itself as you’ll damage it.
Are there compatibility problems with any EF lenses made by Canon?
Basically, no. Any Canon EF-mount lens will work with any Canon EOS camera.
Now, there are minor compatibility issues with IS lenses on certain old EOS cameras - the lenses work, but IS control is a bit weird or the image may shake in the
viewfinder. Luckily this latter does not affect image quality of the photos at all. And autofocus-only EF lenses (a handful were made) are not much use on the oddball
EF-M camera, which was an EOS camera which lacked autofocus circuitry and which can only be used with manual-focus-capable lenses. But these are minor issues
on the whole.
Note that this compatibility issue is only slightly complicated by the introduction of EF-S lenses, in that an EF-S lens is not an EF lens. EF-S lenses, marked with small
white squares rather than raised red dots, can only fit EF-S bodies.
Are there compatibility problems with any EF lenses made by third party manufacturers?
Sometimes. Unfortunately certain third-party lenses not built by Canon, notably many older Sigma lenses, will not work correctly on some newer EOS camera bodies
like the Elan 7/EOS 30/33 and the digital EOS 10D. The most common symptom is the mirror flipping up and then the camera freezing when you try to take a photo.
You then have to switch the camera off to unlock it. The only solution to this problem is to see if Sigma will upgrade the lens for you. If they still have inventory of the
control chip they apparently will happily do so for free.
The only third-party maker of EF-compatible lenses with no major compatibility problems so far is Tamron. Some people have suggested that this is because Tamron
have licensed official lens protocol data from Canon, but Canon USA’s Chuck Westfall has stated repeatedly in public fora that Canon have never licensed their lens
mount protocol to any other manufacturer. So Tamron have either been very lucky or very clever in their reverse-engineering of the Canon lens system. They seem
to be a reasonably safe bet right now for compatibility, given their track record, but it’s impossible to predict future developments in this regard.
The following Sigma lenses require upgrading for compatibility with newer EOS cameras, according to Sigma:
24-70mm 3.5-5.6 aspherical UC
28-80mm 3.5-5.6 mini zoom macro aspherical
28-80mm 3.5-5.6 mini zoom macro aspherical HF
28-80mm 3.5-5.6 mini zoom macro II aspherical
28-105mm 2.8-4 aspherical
28-105mm 3.8-5.6 UC-III aspherical IF
28-135mm 3.8-5.6 aspherical IF macro
28-200mm 3.5-5.6 DL aspherical IF hyperzoom macro
28-300mm 3.5-6.3 DL aspherical IF hyperzoom
70-210mm 4-5.6 UC-II
70-300mm 4-5.6 APO macro super
70-300mm 4-5.6 DL macro super
100-300mm 4.5-6.7 DL
135-400mm 4.5-5.6 APO aspherical RF
170-500mm 5-6.3 APO aspherical RF
8mm 4 EX circular fisheye
15mm 2.8 EX diagonal fisheye
24mm 2.8
28mm 1.8 II aspherical
50mm 2.8 EX macro
105mm 2.8 EX macro
300mm 4 APO tele macro
400mm 5.6 APO tele macro
500mm 4.5 APO
500mm 7.2 APO
800mm 5.6 APO
28-70mm 2.8-4 UC
28-105mm 4-5.6 UC
28-105mm 4-5.6 UC-II
70-210mm 3.5-4.5 APO macro
28-200mm 3.8-5.6 aspherical UC
Can you use old Canon manual-focus lenses with EOS cameras?
Not really. In the years before introducing EOS autofocus cameras, Canon sold many manual-focus lenses for their SLR cameras. The majority of these lenses are of
the FD type. Sadly, FD lenses cannot be used with EOS cameras. The lens mounts are of incompatible sizes and types. This is in contrast to Nikon - most Nikon
manual-focus F-series lenses can be used with most Nikon autofocus cameras.
Now it is possible to use adapter rings to attach FD lenses to EOS cameras. Unfortunately it’s usually not worth the nuisance, in my opinion. There are just too many
drawbacks. I have a separate article on using manual-focus lenses with Canon EOS cameras, if you’d like to learn more.
Can you use non-Canon lenses with EOS cameras?
That depends. Many third party lensmakers - Tamron, Sigma and Tokina being the big three - manufacture lenses specifically designed to fit Canon EOS cameras.
These lenses will, of course, work fine with EOS cameras. The main caveat is the compatibility with the electronics detailed above.
However, if you have a third-party lens which does not physically fit onto your EOS camera then you can obviously assume that the lens will not work with EOS
cameras. Sometimes third party lenses can be adapted to fit EOS cameras by way of metal adapter rings, but it’s often not worth the bother. Autofocus will not work,
and apertures will have to be set manually on the lens. So adapting lenses this way is only worth it if you have a particularly unusual lens or are operating on a
particularly tight budget. For more information have a look at my using manual-focus lenses with Canon EOS cameras article.
I have a consumer Canon camera. Can I put a professional L-series lens on it?
Of course. As noted above, any Canon EOS camera works with any Canon EF (or compatible) lens.
The major issue you really have to be concerned about is weight, since a really heavy lens can strain the lens mount. The answer is to support the heavy lens by the
lens itself - just let the camera hang off the back of the lens. The weight of the camera is not going to strain the lens mount. This applies to all low to midrange EOS
cameras, since even those cameras with metal lens mounts have steel mounts attached to plastic body frames. All larger lenses either come with or have optional
tripod mounting brackets (see below), so you can attach the lens to a tripod rather than the camera body.
Now of course an inexpensive low-end camera won’t have the manual exposure control, focussing speed (AF speed is determined by both the lens motor and the
speed of the camera’s computer and AF sensors) and film-winding motordrive speed to make full use of a top of the line lens the way a professional would like it. And
a small camera will feel unbalanced and cumbersome on a large lens. But it’s better to have a great lens on a so-so body than the other way around. Renting
professional lenses is a great way to learn and practice when you’re on a budget.
This brings up the other issue which might arise - snide looks from camera ignoramuses who think that your little Rebel Ti camera isn’t fancy enough for the 70-200
2.8L you’ve got fastened to it. Ignore them. They’re probably the sort of wealthy dummy who rushes out and buys an EOS 1V and then sticks a cheap consumer lens
on the end.
What’s the big deal about f/8?
Most lenses provide sharpest results when used in the middle part of their aperture range. Lenses usually have performance problems when used wide-open.
Stopping down helps a great deal, but once the aperture becomes too small then an optical phenomenon known as diffraction comes into play and the quality
deteriorates once again. So most lenses work best at around f/8 or f/11 or so.
Naturally this sharpest point (some people call it the “sweet spot”) varies from lens to lens, so some testing would be required to find what’s actually best with a given
lens. And the effect is generally more pronounced with less expensive lenses. Really high-quality lenses are often almost as sharp wide open as they are stopped
down.
What is a focal length multiplier (or cropping factor) for digital and APS cameras?
35mm film has an image area of 24mm by 36mm. These are the exact dimensions of the area on the film to which an image is recorded.
Medium to low-end digital cameras sold today have sensor chips smaller than 24x36mm in size, since producing a 24x36mm image chip is still quite expensive to do.
Similarly, APS film records to an area of film 16.7x30.2mm in size.
The upshot of this is that if you use such a digital or APS camera you’ll be taking photos which do not record the same image size as 35mm film. So it’s like taking a
photo using 35mm film and then cropping out (snipping off) the edges. Imagine drawing a smaller rectangle within a given 35mm photo and then cutting it out - you’ve
got a digital or APS photo.
This cropping factor is often confusingly referred to as a focal length multiplier. This is because the cropping makes, say, a 50mm lens on an APS camera behave
rather like a 70mm lens on a 35mm camera. Not because the focal length has actually changed - it hasn’t - but because of this cropping of the image. The cropping
factor is sometimes specified as a numeric value - 1.3x or 1.6x, say.
If you want to use your lens to take photos of things far away then this might actually be to your advantage. But if you want to use a wide-angle lens then this cropping
factor can be a problem, since wide-angle lenses yield less dramatic results when you crop out the edges.
Some people object to the term cropping factor as well, arguing quite rightly that the issue is a matter of a change in format of the image recording area and using
lenses designed for a different size format. This is true, but people are so used to equating a given 35mm film focal length with a given coverage area (or field of view)
that I think the concept of a cropping factor is convenient and easily understood.
To give an example, let’s say you have a 100mm lens. When used on a 35mm film camera you get a certain coverage of the scene. But if you were to put the same
lens on a digital camera with a 1.6x crop factor (ie: a smaller than full frame sensor) then you would not get the same view of the scene - you’d get less. The view you
would see on your 1.6x digital camera would be the same as if you had a 160mm lens, were there such a thing, on your 35mm film camera.
There’s dust inside my lens!
Unfortunately that’s pretty normal. Only certain expensive L series lenses are sealed to prevent air from entering. All others have a lot of cracks and openings where
air - and dust - can easily enter. Zoom lenses which extend in length when you alter the focal length are particularly vulnerable to this problem, since air gets sucked
in every time you move the lens barrel.
Luckily a little bit of dust inside a lens isn’t going to make much difference, so don’t worry about it. It may be alarming to see the dust specks when you hold the lens
up to a bright light, but it’ll cost an awful lot of money to have a camera repairperson dismantle the lens and clean each internal element. And there’s no guarantee
that the elements will be properly aligned when he or she gives it back to you. So unless the lens is coated with a dusty grey film of dust you shouldn’t have any
problems.
There’s a scratch on the front glass of my lens!
A tiny scratch or chip on the front glass of a lens, alarming as it may look, won’t actually make much difference in image quality under most circumstances since it’s
far enough from the film or image sensor plane not to be in focus. It can, however, affect lens flare, so it’s usually worth filling in the chip with black pen. Having said
that, a large chip (more than a few millimetres long) is obviously undesirable. And chips on the rear glass of a lens are more of a problem.
I’ve seen ads for teleconverters or extenders. Can I put one of these onto my, say, 50mm lens and magically turn it into a 100mm lens?
Yes and no. The answer to this is complicated, but leans mainly towards the “no” side.
Teleconverters, called “extenders” by Canon, are optical accessories which fit between the camera body and the lens. They’re essentially tubes with a few glass lens
elements inside which multiply the focal length of the lens in use - typically by 1.4x or 2x. So a 50mm lens with a 1.4x teleconverter (TC) would take the same
photographs as a 70mm lens, and a 100mm lens with a 2x TC. Think of TCs as magnifying glasses - they enlarge the central portion of the image and cut off the
periphery.
Unfortunately you can’t get something for nothing. And in the case of TCs there are three major tradeoffs.
First, using a TC cuts the amount of light entering the camera. A 1.4x TC costs you a stop of light and a 2x TC costs you 2 stops. This is particularly problematic if
you have a slow lens. Since most Canon cameras (pro cameras notwithstanding) can’t autofocus with lenses slower than f/5.6 you may lose autofocus, or at least
reliable autofocus, if you use a TC. You can sometimes get around this by taping over the teleconverter’s extra pins, thereby fooling the camera into thinking there
isn’t a TC on it at all, but obviously that’ll only really work if there’s enough light coming into the camera for the autofocus mechanism to function. Manual focussing
will also be difficult if the view through the viewfinder is dark, as it will be with slower lenses.
Second, there’s the question of compatibility. Canon manufacture two teleconverters - Extender EF 1.4x and Extender EF 2x - but they are specifically designed to
work only with the handful of expensive telephoto lenses listed below. These extenders have protruding front elements and so physically can’t attach to most EF
lenses - the protruding element simply gets in the way. You could work around it by sticking an extension tube between the TC and the lens, but this would cut even
more light and would also mean you lose infinity focus.
You can avoid this problem by eschewing Canon and going third-party for your TCs. Tamron and Kenko sell their own TCs which don’t have these protruding
elements and so can physically mate with any EOS lens (though TCs in general don’t work very well optically with lenses which aren’t telephotos). These third party
TCs come in varying levels of optical quality. The better quality (more expensive versions, such as the Kenko Teleplus Pro 300 DG) models are generally held as
having decent optics, though not quite as good as the Canon products.
Third, all TCs degrade image quality somewhat. First, you’re adding a bunch more glass between you and the scene you’re photographing and second, you’re using
only part of the centre of your lens. 2x TCs enlarge more of the middle of the lens than the 1.4x TCs, which makes 2x converters worse optically. Now, in the case of a
fancy Canon L series lens and a Canon Extender, this optical degradation will be fairly minimal. However, if you take your typical cheap consumer zoom lens and slap
a third-party TC on it you’ll find that the results will be less than stellar. In fact, in such cases you’re probably better off simply cropping and enlarging part of a photo
taken without a TC and leaving it at that. The quality would be higher and you’d save money.
So. The answer to this question really depends. If you have a professional lens and a quality TC then, yes, you’ll be able to increase your focal length at the cost of
some light. But if you have your typical consumer lens then there’s probably no point buying a TC - you’ll end up with fairly crummy photos.
Canon extender compatibility list:
The Canon extenders are physically compatible with all prime (fixed focus) Canon EF lenses with a focal length of 135mm or longer except for the 135mm 2.8 SF.
They are also compatible with a handful of recent L series zoom lenses. The full official list is:
• 70-200mm 2.8L
• 70-200mm 2.8L IS
• 70-200mm 4L
• 100-400mm 4.5-5.6L
• 400mm 4 DO
• 135mm 2L
• 180mm 3.5L Macro
• 200mm 1.8L
• 200mm 2.8L
• 300mm 2.8L IS
• 300mm 4L
• 300mm 4L IS
• 400mm 2.8L IS
• 400mm 5.6L
• 500mm 4L IS
• 600mm 4L IS
• 1200mm f/5.6L
Consult Canon when checking out newer L series lenses introduced since this list was written, and you’re on your own if you use third party lenses. You can also use
Canon extenders with Canon TS (tilt-shift) lenses, but it should be noted that the TS lenses can’t report to the camera that the extenders are there.
Auto focus is not supported by non-pro EOS cameras when the 1.4x converter is used with 100-400mm 5.6L, 400mm 5.6L, 500mm 4.5L, 1200mm 5.6L, and with the
180mm 3.5 Macro when it’s focused closer than 0.8 meters, or when the 2x converter is used with the 70-200mm 4L, 100-400mm 4.5-5.6L, 180mm 3.5L Macro,
300mm 4L IS, 300mm 4L, 400mm 4 DO, 400mm 5.6L, 500mm 4L, 500mm 4.5L, 600mm 4L, and the 1200mm 5.6L.
Note that there are two generations of the Canon Extenders - the original 1.4x and 2x models and the mark II successors, which add improved weatherproofing. The
1.4x II is said to be optically identical to its predecessor but the 2x II has minor optical enhancements.
I want to take close-up (macro) photos. What do I need?
Close-up or macro photography is a lot of work, but it can also be extremely rewarding. Detailed close up photos of tiny objects can literally introduce you to another
world. Here are some reasons why it’s a very challenging area of photography.
• Most camera lenses are not capable of focusing close enough to take decent macro photos. Even lenses marked “MACRO” can’t necessarily be used for
interesting macro photography - see the section above.
• The close-up exposure mode (indicated by a flower icon) on most EOS cameras does not really help macro photography at all. All it does is set certain
camera characteristics, such as metering method and motor-wind settings, to make macro photography slightly easier. The icon mode does not alter the lens
characteristics in any way.
• As noted above, depth of field is incredibly shallow when it comes to extreme closeup photography. This means that your focusing has to be absolutely
dead-on.
• The usual solution to excessively narrow depth of field problems is to stop down the lens. The problem with that in macro photography is that stopping down
the lens limits the amount of light coming into the camera, which can cause problems with lighting.
• In fact, since working distance (the distance between the end of the lens and the subject) is often really limited, lighting is usually a problem even if you
don’t stop down a lot. Simply because the lens itself blocks a lot of light. For that reason flash units are a very common macro photography accessory, particularly
ring-shaped flash units which fit around the end of the lens itself. Such macro ring light flash units often have two tubes so you can control the relative brightness of
one side of the image compared to the other. If you’re on a really tight budget, however, you could try putting a translucent white milk jug around lens and shining
really bright light onto it.
• Unfortunately, auto focus often doesn’t work very well if at all under macro conditions, particularly if you’re using an extension tube. A camera with a
manual focus assist aid in the viewfinder screen is a useful accessory, as is a magnifying attachment for a viewfinder so you can see the camera’s focus screen more
clearly.
• Focusing is often so tricky that experienced macro photographers don’t adjust focus using the manual focus ring on the lens. Instead they physically move
the camera closer to or further away from the subject in order to focus. You can buy convenient adjustable rail systems (macro focus rails with one or two rails) that
slide the camera back and forth for this type of precise macro focussing.
• When you’re dealing with closeup work the tiniest motion is magnified. Let’s say you’re shooting a spider’s web on a misty morning; the dewdrops
clustered on the threads like tiny glass spheres. The problem is that the gentlest breeze can set the entire web bouncing, quivering and vibrating so badly that you get
motion blur. This is also why you typically need a tripod to do it right. Handholding a camera introduces too much camera blur unless you use a motion-stopping burst
of light from a flash unit.
Here are your six basic choices if you want to take a closeup photograph.
1) Buy a true macro lens capable of reaching 1:1 magnification.
(see the previous section for an explanation of 1:1 magnification) This is the most expensive option, since true macro lenses aren’t cheap. However, it’s usually the
most high-quality option. True macro lenses come in a variety of focal lengths, from 50mm to 90 or 100mm to 180mm. The advantage of the longer lenses is that they
give you more working distance from your subject. A 50mm macro lens isn’t very useful for shooting, say, dragonflies in the wild since you have to be really close to
them. A 180mm macro lens, on the other hand, lets you maintain more distance so you’re less likely to frighten them off. Of course, 180mm macros are pretty
expensive. A 90/100mm lens is usually the better compromise in terms of working distance and cost.
There are six true macro lenses in the EF lineup which can do 1:1. There is the 50mm f2.5 Macro (which technically only goes to 1:2 or half-size and requires the
optional Life Size Converter EF to reach true 1:1), the discontinued 100mm 2.8 Macro, the newer 100mm 2.8 Macro USM, the expensive 180mm 3.5L Macro USM
and the EF-S 60mm 2.8 macro, which only fits EF-S-compatible cameras. There is also the unusual MP-E 65mm lens; see below. Another popular macro lens worth
considering, though not from Canon, is Tamron’s 90mm macro lens.
2) Buy a diopter (macro filter).
These are round screw-on lenses which fit on the end of a lens in exactly the same way as a filter and which act essentially like magnifying glasses. The amount of
magnification you get depends on both the strength of the diopter and the focal length of the lens to which you attach it. Diopters cost no light but can degrade the
image slightly, depending on the quality of the product. Still, they’re lightweight and portable and, since they cost no light, usually permit autofocus to work. They’re
usually a good approach for beginners looking to explore macro photography.
You can buy both single-element diopters which contain a single piece of glass and two-element diopters which contain two. Two-element diopters are what you want -
they cost more but provide vastly better optical quality by correcting certain optical aberrations. Diopters are available in a variety of physical sizes which match
popular lens filter sizes, but can be adapted with step rings just like ordinary filters if necessary.
Canon sell two two-element diopters - the 250D and the 500D. The former is intended for shorter focal length lenses, from about 30-135mm. The latter is meant for
longer focal length lenses, from about 70-300mm. You can also buy a 500 diopter which, since it’s a single-element accessory, isn’t as good. You don’t have to buy
Canon’s diopters, of course - Nikon also sell highly-regarded diopters (the Nikkor 3T, 4T, 5T and 6T closeup attachments) which are actually usually less expensive
than Canon’s. Bob Atkins’s Web site has a comprehensive table of magnifications available using different diopters on different lenses.
3) Buy an extension tube.
These are hollow plastic tubes which fit between the lens and the camera body, thereby increasing the distance of the lens to the camera and thus reducing the close
focus distance of your lens. (ie: they let you move the lens closer to the subject while retaining focus) Attaching an extension tube means you lose infinity focus but
that’s obviously not an issue if you’re using the tube to take closeup pictures. Tubes also reduce the amount of light reaching the film or image sensor (because
moving the lens further from the film or sensor plane causes the light to spread out across a larger area).
Unlike diopters, however, they do not affect image quality at all as no optics are involved. The magnification you get depends on both the length of the tube or tubes
used and the focal length of your lens - Bob Atkins’ table lists some common combinations. Some lenses, particularly wide-angle and specialized lenses such as the
15mm 2.8 fisheye, 14mm 2.8L and MP-E 65mm 2.8, don’t work properly with tubes. If you have EF-S lenses for newer EOS digital cameras then you’ll need the mark
II Canon extension tubes (the Extension Tubes EF 12 II and EF 25 II), since the earlier versions don’t mate with EF-S lenses - EF-S lenses extend deeper into the
camera body than EF lenses.
Canon sell a couple of extension tubes, but they’re pretty expensive. The three-tube set from Kenko is a better deal - it’s fairly well made and contains a 12mm, a
20mm and a 36mm tube. However, current Kenko tubes are compatible only with EF lenses - they do not physically mate to EF-S lenses.
Adjustable bellows are also used for closeup photography - they’re basically adjustable tubes when you get down to it. Novoflex sell an EOS-compatible bellows or
you could buy the old Canon FD bellows and adapt it using the FD to EOS macro adapter. Bellows are typically used with movable rails for precise focussing.
4) Reverse a lens by mounting it onto the camera backwards.
Doing so requires some sort of adapter with a standard EOS lens mount on one end and a filter ring on the other which attaches to the filter ring of the lens. People
often make such things at home by gluing a filter ring to a drilled-out body cap. Reversing a lens like this is a very old photographic trick for doing macro
photography.
This technique is a problem for EOS lenses, however, since EOS lenses require electrical connectors in order for the aperture diaphragm to operate. There are at
least three possible solutions for this. First, you could set the lens aperture to whatever you want it to be, press the depth of field button on your camera to stop down
the lens and then detach the lens. The lens diaphragm should stay wherever it was when you removed the lens and you can then reverse the lens and use it. This isn’t
terribly convenient, of course, since you can’t adjust the aperture without remounting the lens. Second, you could use a non-EF lens. Any 35mm lens will do, really,
since you’re mounting it backwards and not using the normal lens mount. Third, you could buy Novoflex’s rather expensive lens reversal adapter, which contains the
necessary wires and connectors to let the electromagnetic diaphragm operate correctly.
5) Attach a reversed lens to an existing lens.
Another old macro trick is to attach a 50mm (normal) lens to the end of another lens, but backwards. (ie: the filter threads of the 50mm lens are attached to the filter
threads of the camera-mounted lens by means of a special lens-reversing or macro-coupling ring) You won’t be able to adjust the aperture of the reversed lens if it’s
an EF-type lens, but there’s nothing stopping you from using a non-EOS lens in this way, as above. A 50mm lens reversed on a 100mm lens can give you 2x
magnification, for example, albeit with a fair bit of light loss.
6) Buy the Canon MP-E 65mm lens.
This is an unusual and specialized lens that’s designed solely with macro photography in mind. It can’t be used for normal photography, unlike the other Canon macro
lenses, as it starts out at 1:1 magnification. It goes from there to 5:1 magnification. At this magnification an object 5mm x 7mm in size will fill the entire frame of
35mm film.
Though intriguing, it has a number of drawbacks. First, you can use it for super closeup photography and nothing else since it lacks infinity focus. Second, it suffers
from the usual problems of macro photography - very narrow depth of field and the difficulty in illuminating objects adequately given the short working range. Third,
ambient light metering works only with EOS 1 series cameras - all other EOS cameras can only be used with TTL flash metering. And fourth, the focussing screen of
your camera may not be precise enough for accurate focussing.
Can I use the Canon 100mm macro lens for portraits?
Absolutely. The 100mm 2.8 macro and macro USM lenses are both excellent portrait lenses in addition to being great macro lenses. The only problem is that they’re
extremely sharp lenses, and some people prefer softer lenses for portraiture, particularly of women. If you’re in that camp you could always slap a soft focus filter
onto the lens.
What happened to the solid all-metal lens barrels of yesteryear? Why is everything today made of plastic?
It’s true that a lot of lens barrels of the 60s and 70s were solid finely-crafted metal masterpieces with smooth focussing spiral-shaped helicals and precisely-machined
parts. Whereas today many lens barrels are made largely of plastic. There are a number of reasons for this - the rise of autofocus, rise in labour costs, lower SLR
sales, improved plastics technology, a desire to make lighter-weight gear, increased profit margins for manufacturers and so on.
Certainly the rise of autofocus is a major factor. Autofocus lenses with geartrains (ie: ring USM lenses excepted) require a bit more looseness and play in the
geartrain system. They also don’t usually use long focussing helicals as that would take more battery life and time to focus. Manual focus lenses with helicals, by
contrast, can be machined to very tight tolerances.
However, there are advantages to increased use of plastics in lens construction. Quality plastic is fairly resilient and doesn’t dent like metal, plastic is obviously much
lighter than metal, plastic components are less expensive to produce and can in theory result in lower prices to the consumer and so on.
So, while the old manual-focus lenses may feel great to hold and use and exude that terrific sense of precise quality that plastic lenses simply do not do, it’s unlikely
that less expensive autofocus lenses will ever be made with metal barrels. Note, however, that many Canon L series lenses use solid metal barrels and have
reasonably tight-feeling manual focus rings. So if you’re willing to spend the money you can still get metal lenses and retain autofocus.
Grades of plastic
There’s also plastic and there’s plastic. Canon have used, very roughly speaking, three different grades of plastic shell material for their EF lenses over the years.
The first generation of EF lenses used a fairly brittle hard type of plastic, which I call type 1. (though that isn’t, of course, an official Canon designation) This material
was moulded with a slight rough texture and the lenses had basically parallel lines to their cylindrical barrels, with little if any tapering. Focus and zoom rings often did
not have rubberized surfaces. The 50mm 1.8 mark 1 is an example of this late 80s type of design. In my experience, though this purely anecdotal, type 1 plastic is a bit
more likely to crack upon impact than later plastics.
The second generation, particularly black L lenses and advanced amateur lenses, are made of a more resilient hard black plastic, which I call type 2. These lenses
have relatively little texture - they’re either quite smooth or have a subtle hammered finish. These barrels tend to have subtly tapered barrels rather than simple
cylinders, and have rubberized zoom and focus rings. The 28-105 3.5-4.5 USM is an example of a midrange zoom of this construction, and the heavier 135mm 2.0L
USM is an example of an L lens using this construction, albeit with thicker plastic and a generally sturdier design. Lenses of this type first came out in the early
1990s, and seem to me to be slightly less likely to crack upon impact - the plastic has a tiny bit more inherent flex to it.
Finally, inexpensive cheapie lenses over the past few years have been made of lightweight smooth plastic which I characterize as type 3. These lenses often have
somewhat exaggerated rubber rings for zoom grips, and later models (late 90s on) have shiny chrome rings around the end to impress less experienced consumers.
The EF-S 18-55 3.5-5.6 is a typical example of this type.
Lens-related technical terms and vocabulary.
What is focal length?
The focal length is a basic optical property of any lens, and the most important one to a photographer. The simple way to think of the focal length is to think of it as a
numerical value, expressed in millimetres, which represents how much of a given scene (the coverage area) a lens can take in.
Focal lengths for Canon SLR lenses range from ultra-wide (14mm) to incredibly long telephoto (600mm and 1200mm). The typical range of an affordable lens or
lenses is from 28mm to 105mm or so.
Why, then, these strange values in millimetres? Why not indicate the angle of view taken in by each lens instead? Well, partly for historical reasons and partly for
practical reasons. The technical description of focal lengths is rooted in the mathematics of optics - it’s the distance between the focal plane and the rear nodal point
of the lens, given infinity focus. How this bit of Martian translates to the field of view depends on the size of the imaging area being used, which can be different
between 35mm film cameras, APS cameras and some digital cameras. And as for practical reasons, the focal length of a lens is an innate property of the lens, but the
actual coverage area of the scene depends on the size of the image format used.
So note that crucial point - all the examples I gave above are for a 35mm film camera or full-frame EOS SLR only. If you were to use a 28mm lens on an APS camera
or a digital camera with an image sensor smaller than that of 35mm film (ie: most digital cameras sold today) then you would have a much narrower field of vision than
if you were to use the same lens on a 35mm film camera. For more details see the section on focal length multipliers/cropping factors.
The same focal length system is used to describe lenses for other types of cameras as well, such as medium format cameras. But the area taken in by a lens on a
medium format camera will be totally different from that of a lens of the same focal length on a 35mm camera, because the area covered by medium format film is
considerably larger.
What is a lens aperture or f stop?
The aperture of a lens is its second most important optical property after its focal length. Consider the human eye. It has a coloured iris with a pupil which can dilate
or contract in order to let in more or less light, depending on ambient light conditions. When it’s dark the pupil opens up to let in as much light as possible. And when
it’s sunny the pupil contracts to prevent the bright light from overwhelming the eye. Most camera lenses have a device analogous to the iris - a metal or plastic
diaphragm which can be adjusted in size to control the amount of light entering the lens.
The variable-sized hole in the diaphragm is known as the aperture, is analogous to the pupil of the eye, and is indicated numerically by an f-stop or f-number value.
This value, the relative aperture of a lens, describes the amount of light that a lens lets in. The value is relative because it is equivalent to the focal length of the lens
divided by the size of the lens aperture, not the physical dimensions or anything.
For example, if you were to take a 50mm lens with a 6.25mm diameter aperture you’d have a lens set to f/8 (since 50/6.25 = 8). Generally each increase or decrease in
f-stop value either doubles or halves the aperture size. Since f-stop values are relative to the focal length, each camera lens should let basically the same amount of
light through at the same f-stop value regardless of focal length. (barring complex technical factors such as light loss from large numbers of elements and so on, but
we won’t get into that here)
The usual f-stop range on 35mm and digital SLR camera bodies is:
1.0 1.4 2 2.8 4 5.6 8 11 16 22 32
though most camera lenses are only optically capable of a subset of that overall range.
The relationship between these values involves halving and doubling the amount of light. Going from f/2.8 to f/4, for example, involves a halving of the aperture size.
Each number is approximately 1.4x more than its previous stop since 1.4 is the square root of 2 (to one decimal place), though since the specific numbers derive from
tradition they are not always spot on. Lenses for larger camera systems such as large format cameras usually have even smaller apertures - going to f/64, for
example.
This series of numbers may look difficult to work with, but in fact there’s a fairly simple way to recall it. Just remember that the first two values are 1.0 and 1.4
respectively. Each following value then doubles by every other value. So 1.0 becomes 2, then 4, then 8 and then 16. 1.4 becomes 2.8, then 5.6, 11 and 22. (the only
minor glitch, of course, to this handy mnemonic scheme is between 5.6 and 11)
Confusingly enough, when the number is small (eg: f/2.8) then the lens diaphragm is open wider (“opened up”) and thus more light enters the lens. If the number is
large (eg: f/22) then the lens diaphragm is closed smaller (“stopped down” or “closed down”) and thus less light enters the lens. In addition to altering exposure times,
the aperture setting also affects depth of field.
The letter f is frequently italicized for good looks, and a slash is often placed between the letter f and the numerical f stop value to indicate that the f-stop value is a
fraction of the focal length. eg: f/4 means that the aperture is a quarter of the focal length. The letter f stands for “focal,” “factor” or “focal length” depending on who
you talk to, and the number is also often stated as a ratio. (eg: 1:2.8)
Note that not all lenses have adjustable diaphragms. Many types of lenses, though not usually those sold for use with EOS cameras, have fixed apertures. Mirror
lenses, for example, fall into this category since they lack (adjustable) diaphragms. Really crummy cameras - disposable cameras being one example - also have fixed
apertures. These two examples aside, however, nearly all lenses sold for use with EOS cameras have adjustable apertures.
What is a slow lens or a fast lens?
These are colloquial expressions describing the maximum aperture value or values of which the lens is capable. Slow lenses have a very small maximum aperture,
which means less light enters the lens and so longer time periods are required to expose the film or image sensor. Fast lenses have a very wide maximum aperture
and so shorter time periods are required to expose the film or image sensor.
The larger the maximum aperture of a lens the more light it lets in. And so faster lenses are generally more desirable than slower lenses. First, fast lenses let you
take photos in lower light levels using available light rather than blasting the scene with ugly light from a flash unit. Second, you can see through the viewfinder better
since fast lenses let in more light and so the view through the finder will be brighter with a fast lens.
As explained above, lens f stops are ratios, and so smaller numbers indicate larger apertures. A lens with a maximum f stop value of 1.4 is, therefore, fast. And a lens
with a maximum f stop value of 5.6 is slow by comparison. However, f stop numbers are the ratio between the focal length of the lens and the aperture, which means
that it’s very easy to design a fast 50mm lens (1.8 is a typical maximum aperture value) but very hard to design a long 200mm telephoto lens with a maximum
aperture so large.
In fact, designing fast lenses in general is more complex and expensive than designing a lens with a small maximum aperture, so fast lenses tend to cost more than
slow ones. It’s also harder to design and build a fast zoom lens than it is a fast prime (fixed focal length) lens. Faster lenses are also usually physically larger than
slower lenses of equivalent focal lengths. The reasons for all this are tied into the complex mathematics of optics.
Note that autofocus lenses for EOS cameras have the focus motor built into the lens, not the camera. And some lenses focus more rapidly than others. So sometimes
you hear people talking about a lens having a fast or slow focus motor speed, which is a separate matter altogether from the optical properties of the lens.
What is depth of field?
When you focus on something, the subject isn’t the only thing that’s going to be sharply focussed. Certain objects closer to you and further away from that subject will
also be in acceptable - though not quite as sharp - focus. The distance range within which these objects appear to be in reasonable focus in your final photograph is
known as depth of field. Being able to control depth of field is an important photographic skill since it can affect the appearance of a photograph dramatically.
For example, let’s say you’re taking a portrait of someone outside. And let’s say that the reason you’re doing so outside is to get nice natural lighting, but you don’t
care so much about the background as such. Maybe you’re in a park and you don’t want to show a cluttered background of trees, grass and bushes. In this case you’ll
want a narrow depth of field and focus on the person’s eyes since they’re the key thing you want to have in focus. If you have a narrow depth of field then the
background will be thrown nicely out of focus and you’ll just have a pleasingly blurry green background to your portrait.
But let’s say you want to take a nature photograph of a flower in a dramatic mountain landscape with an interesting sky. In this case you’ll probably want everything
from the flower to the sky to be sharply in focus. This would require great depth of field.
There are three factors which control depth of field on a given camera. They are as follows:
Aperture.
The aperture (f stop) to which a lens is set is a very important factor governing depth of field. The larger the aperture (smaller the f stop number) then the smaller the
depth of field and vice versa. So if you’re shooting something in low light conditions and open your lens up to f/1.8 in order to admit as much light as possible you’ll
find you have a really narrow depth of field, which can be a real problem sometimes, since precise focussing is required. Conversely if you’re shooting outdoors on a
bright sunny day you may find you’ll need to stop down a long way to get the shutter speed you want, but this can result in too great a depth of field for some
applications.
Focal length.
The focal length of your lens also makes a tremendous difference. Lenses with short focal lengths (wide angle lenses) have wider depths of field available and lenses
with long focal lengths (telephoto lenses) have shallower depths of field available. This is generally a good thing. If you’re using a really wide lens for landscape shots
you’ll be able to get huge areas of scene in sharp focus. But if you’re using a really long telephoto lens for bird photography then your depth of field will be really
shallow and you’ll be able to isolate the bird in the landscape nicely.
Subject distance.
Finally, the distance from the lens to the subject also affects depth of field. If you’re really close to your subject, such as in macro photography, then depth of field will
be shallow. But if you’re taking a photo of something that’s a long way away then your depth of field will be deeper.
Naturally all three of these factors work together, so you can adjust all three factors to achieve the effect you’re looking for.
It should be noted that the size of a camera’s image area also dictates the depth of field. A camera with a large image area - say a medium-format or large-format
camera - is capable of a much more shallow depth of field than a camera with a smaller image area. This is why consumer digital cameras, which have tiny image
sensors, have such deep depth of field. However, you can’t change this particular factor without switching cameras. The other three factors above are adjustable on
any given EOS camera.
It should also be noted that this is a very non-technical description of what depth of field is all about. To be more accurate about it you need to go into a lot of math
and a definition of the circle of confusion and a consideration of the print size and so on. But the simplified stuff above is adequate to get a grasp of how to control
depth of field adequately to make your photos look the way you want them to.
What is a bayonet mount?
Canon EF mount lenses are of the “bayonet” type. This means that the lenses have mounting lugs (three in the case of EOS lenses) which slot into the camera body
mount. You then rotate the lens a partial turn to lock it into place with a click.
Most camera makers these days use bayonet-style mounts, though other types were popular in the past. For instance, older Pentax and Leica cameras used
screwmount systems - you simply screwed the lens into the camera body’s threaded mount. The lens system used by Canon prior to the introduction of EOS was the
FD system, which used a “breechlock” mount system with a rotating friction ring.
Lens hoods often fasten by means of bayonet mounts. Some filters for certain European lenses also use bayonet mounts, though Japanese makers generally use
threaded filter mounts.
It’s not clear why the lens mounts are called bayonet mounts. The two theories I’ve heard both stem from bayonets, the knives which soldiers fasten to the end of
their rifles. One theory, which is probably utterly apocryphal, suggests it’s a gruesome joke deriving from the instructions given to soldiers on how to use their
bayonet - thrust in and twist. The more probable and prosaic theory is that the term derives from the design of bayonet mounts on rifles.
What does a Roman numeral on a lens refer to?
Canon, like most Japanese lens makers, use the optical specifications of a lens to distinguish one model from another. (European makers have traditionally come up
with fun names resembling Star Trek planets, like “Tessar,” “Biogon” or “Super Angulon,” to describe their lens designs) But sometimes a maker will produce new
models later on which happen to have the same basic specifications as previously-made ones. To distinguish these lenses one from another Canon will add a Roman
numeral to the end of the lens specification, starting with II. For this reason you will never see a lens marked with a I, though people often refer to “mark I’” lenses
when subsequent models are released. You will, however, see lenses marked with II, III, IV, etc. These are commonly referred to as mark II, mark III, etc, lenses in
common parlance.
Sometimes these later lenses are an improvement over the original, sometimes they’re worse and sometimes they are almost identical bar some cosmetic changes.
For example, the 50mm 1.8 II is markedly inferior to its predecessor in build quality but has the same great optics, the 28-80 3.5-5.6 USM II is entirely worse in every
respect to the mark I edition, but the 28-105 3.5-4.5 and 28-105 3.5-4.5 II lenses are basically the same with slight cosmetic differences. There’s unfortunately no way
to tell from the Roman numeral designation itself whether or not a later lens is better or worse. I try to identify these differences between versions in my lookup page,
so that’s a good starting point.
Canon also release updated versions of lens hoods using Roman numeral designations, as described above.
What is the difference between the various kinds of lens motors (AFD, MM, USM)?
Unlike most camera makers Canon chose to position the auto focus motor inside the lens barrel rather than in the camera body when they designed the EOS system.
This was arguably a wise move, since it means auto focus motor can be tailored to the requirements of each lens. A big telephoto lens can have a large motor and a
small normal lens can have a more compact motor. By contrast, systems which rely on the auto focus motor being only in the camera body don’t have this flexibility -
the motor is always the same regardless of the lens used unless you change camera bodies.
So. Canon employ a number of different motor technologies in their lenses. The first two types are never identified specifically on the exterior of the lens. You have to
look up in Canon’s product literature to see which type of motor a given lens uses.
Traditional electromagnetic motor drives.
Such motors contain tiny wound coils of wire and rely on electromagnetic principles to turn a shaft. Little cogwheels and gears are then used to translate this
rotational motion into the movement needed to adjust lens focus.
Arc-form drive (AFD).
Generally used in a number of older lower-cost lenses, AFD motors are simply little electric motors which drive a geartrain. They’re somewhat noisy - electric buzzing
and grinding of gears - and not terribly fast. This isn’t a big deal on smaller lenses since the distances the motors must move the focussing elements aren’t very far.
However, telephoto lenses with AFD motors can be quite sluggish.
Micromotor (MM) drive.
Generally used on a few older lower-cost lenses. Similar to AFD - slow and noisy and based around an electric motor driving a geartrain. Some particularly low-cost
lenses use micromotor drives with rubber belts.
Ultrasonic motors.
Ultrasonic motors do not rely on magnetic coils like most electric motors. Instead they use extremely high-frequency vibrations which translate into circular motion.
The result is a very fast and pretty well silent (to human ears, anyway) lens motor. There are two basic types employed by Canon.
Ring ultrasonic (USM) drive.
The kind you want. These motors consist of two metal rings which vibrate at a very high frequency. (have a look here for photos of these rings) Ring ultrasonic lenses
are great because they focus quickly and silently and also support full-time manual (FTM). There are actually two variants of this design - see the FTM section
below.
Micromotor ultrasonic (USM) drive.
This kind is less desirable. It’s a form of USM motor that Canon designed for their cheapie lenses so they can bill them as ultrasonic for marketing purposes. An MM
lens replaces the standard magnetic motor with an ultrasonic motor but retains the usual geartrain setup. Such lenses are still reasonably quiet, though not as quiet as
ring ultrasonic motors, but usually lack FTM - see below.
Note that, while all lenses with “USM” in the name contain an ultrasonic motor, Canon do not distinguish between ring and micromotor USM drives in the name - you
have to look up the specs for the individual lens to find that out. Also, most non-L lenses with USM drives have striped gold lines painted around the end of the barrel.
However, all L lenses have red lines painted around the end, whether or not they use USM (ie: Canon never have two painted rings around their lens barrels, and the
red L line takes priority over the gold USM line).
What is full-time manual (FTM)?
As noted above, Canon EF lenses with AFD (arc form drives) and MM (micromotor) drives use very simple autofocus mechanisms which rely on electric motors and
geartrains - rows of tiny cogwheels. Unfortunately, turning such a focus system by hand can damage the geartrain, so such lenses have a switch mechanism which
disengages the cogwheels when you focus manually. There is thus no way for you to focus manually when the lens is switched over to autofocus mode.
However when Canon introduced lenses with USM (ultrasonic motor) autofocus systems they also introduced full-time manual focussing (FTM). Such lenses allow
you to adjust focus manually even when the AF/MF switch is set to autofocus. This is very handy, as it lets you adjust or touch up focus without having to flip the
switch.
There are a few points to keep in mind here.
• There are actually three different types of USM motors, although there’s no way to distinguish them apart by looking at them - the lenses are all simply
marked “USMThe best USM motors are those used in most midrange and L series contemporary lenses - ring USM motors. A ring USM motor consists of two metal
rings which vibrate at high frequencies, resulting in rotational energy. Full-time manual on a ring USM lens is easy - there’s a simple friction clutch which means
you’re simply turning the whole motor by hand when you rotate the focus ring. This means you can focus the lens manually at any time, even if the camera is turned
off or the lens isn’t attached to a camera.
• The second type of USM is the earliest design, and seen only on a few older lens designs and some longer telephotos. These are electronic focus ring USM
lenses which can only focus manually when the camera is actually turned on. This is because turning the focus ring sends electronic commands to the lens motor,
ordering it to rotate. The following lenses are old-style electronic full-time manual USM lenses:
EF 50mm 1.0 L USM
EF 85mm 1.2 L USM
EF 85mm 1.2 L USM II
EF 28-80mm 2.8-4 L USM
EF 200mm 1.8 L USM
EF 300mm 2.8 L USM
EF 400mm 2.8 L USM
EF 400mm 2.8 L II USM
EF 500mm 4.5 L USM
EF 600mm 4 L USM
EF 1200mm 5.6 L USM
• Finally, there are micromotor USM lenses. These are mostly inexpensive consumer lenses which do not support full-time manual, because they still use a
mechanical geartrain. Arguably these lenses are barely USM, since the only real advantage they have over regular motors is that they’re slightly quieter.
There are a couple of exceptions to confuse matters, however. The 50mm 1.4 USM and the newer 28-105 4-5.6 USM lenses contain slip clutch mechanisms which let
you use FTM in a fashion similar to a ring USM lens.
• Adjusting focus manually is a bad idea when the lens motor is in the process of turning, since you’d be fighting the motor and straining it. Wait until the lens
motor has stopped operating before turning it by hand.
• Finally, adjusting focus manually is also a bad idea when the camera is in AI Servo mode, since the AF motor can kick in at any time.
Do USM lenses take better photos than non USM lenses?
No. USM (ultrasonic motors) are autofocus mechanisms. They in no way affect the optical quality of a lens.
Of course, since USM lenses focus faster and more quietly than non-USM lenses there’s the possibility that using one might help you get a photo that you might not
have got with a slower or louder autofocus lens. But that again is unrelated to the optical quality itself.
This confusion may come in because Canon only put ring USM drives into their midrange and pro (L series) lenses. You can’t buy cheap Canon lenses with ring USM
- only micromotor USM (see above). But again this is no guarantee of anything, since there are plenty of Canon lenses - particularly their older prime lenses - which
lack USM but which have excellent optical quality.
What is image stabilization?
Image stabilization or IS is a Canon technology that optically corrects for camera motion when you take a photo. Since camera motion - caused by handholding the
camera, for example - can result in blurring of the image at slower shutter speeds, IS can result in sharper photographs when fast shutter speeds are not possible.
IS is a fairly complex technology involving motion sensors, microcomputer chips and small motors to move key lens elements. There is, therefore, a price premium for
IS-capable lenses. But they can be very convenient - when handholding a camera you can easily gain a stop or two over using a non-IS lens.
However, remember that IS does not increase the maximum aperture of the lens or anything. An IS lens with a maximum aperture of 3.5 still has a maximum aperture
of 3.5. IS simply lets you use a slower shutter speed than would otherwise be possible when you’re handholding the camera, by compensating for camera motion. So
you won’t necessarily be able to get that narrow depth of field that you could with a faster lens - which could be a drawback or a benefit depending on your point of
view.
IS has a few other drawbacks over faster lenses as well. Earlier IS lenses tended not to perform very well when mounted on a tripod when the IS mechanism was
engaged. Consumer IS lenses also do not work very well when panning (tracking a moving object), though pro IS lenses do. IS does not help you if the subject is
moving - it compensates only for camera motion. IS doesn’t help freeze subject motion and in fact will probably make things worse by letting you use a much slower
shutter speed than a fast lens. Some people find the slight swimming motion in the viewfinder when using IS a bit dizzying and IS uses a little more battery power than
no stabilization at all. Finally, some earlier film EOS cameras are not entirely compatible with IS lenses and have minor inconveniences, such as viewfinder shake
once a photo has been taken (though this does not affect the picture quality).
Nonetheless, these drawbacks aside, most people find IS quite valuable, particularly on long telephoto lenses.
Canon were the first company to include image stabilization technology in SLR lenses, though Nikon actually pioneered the field with a stabilized-lens point and shoot
(the Zoom-Touch 105 VR) in 1994. Today Nikon sell a range of VR (“vibration reduction”) SLR lenses; the main difference being Nikon sell mainly to the high end
lens market where Canon sell a variety of IS lenses covering the mid to high end markets. Sigma have also released a number of image-stabilized lenses. Canon IS
technology is built into the lens, like the Mega Optical Image Stabilizer (Mega OIS) system used by Panasonic. These both differ from the Minolta-developed Super
SteadyShot stabilization technology used by Sony, which is built into the camera body. Building anti-vibration technology into the camera has the advantage of making
the feature available to any lens attached to a supported camera, but it has the disadvantage of not being tailored to each focal length range.
What is distance data and which lenses support it?
Many Canon EF lenses have the ability to send distance data to the camera. For example, if you’re currently focussed on an object 4 metres from the camera then the
lens would send that approximate distance data to the camera body.
Canon have built and sold lenses since 1990 with this data, but it wasn’t until 2004, with the advent of E-TTL II flash metering, that Canon really put it to good use.
E-TTL II has the ability to factor distance data into flash metering calculations under certain conditions. This distance data can improve the reliability of flash
metering when it’s available and appropriate.
For more information on this topic please consult my EOS flash photography article, which has a section on E-TTL II and a list of Canon EF lenses capable of
returning distance data.
What is a lens element?
There’s some confusion of terminology here. The word “lens” refers both to a single chunk of shaped glass (think of the single lens of a magnifying glass) and the
tube-shaped device containing such lenses which you fasten to the end of your camera.
A lens element is a single piece of shaped glass or crystal. Camera lenses these days contain anywhere from 4 lens elements and up. They are frequently arranged in
optical groups within the barrel. For that reason you may hear of a given lens having, say, 18 elements in 15 groups.
There are complex tradeoffs made in lens designs, so the number of elements and groups isn’t always the most reliable indicator of image quality. Simpler lenses with
just a few elements tend to offer good results because they are so simple. Flare in particular (light reflection between elements in this case) is vastly reduced.
However, wide angle and telephoto lens designs generally require more elements to correct for various optical aberrations.
What is a lens coating?
As anyone who has looked through a window knows, glass both reflects light and lets light pass through. And reflections can easily happen at oblique angles as well as
when you look at a lens straight-on. Camera lenses suffer from the same basic problem of reflections as windows. And excessive reflections within the lens can result
in lens flare - either a generalized loss of contrast or bright reflected blobs appearing in the picture.
The invention of lens coatings by German lensmaker Carl Zeiss in the mid 1930s revolutionized lens design. Such coatings are fine layers of transparent material
which are applied to the surface of lens glass and which minimize internal reflections within the lens. All modern camera lenses, including Canon EF lenses, are
multicoated to reduce reflections. Canon refer to their technology as SSC, or Super Spectral Coating.
You can easily tell a coated glass surface from an uncoated one. An uncoated piece of glass reflects a lot of light, and reflected white light is also white. A coated piece
of glass, however, reflects far less light and the light that is reflected is often greenish, purplish or reddish. These apparent colours, it should be noted, are artefacts of
the way coatings absorb reflections, and do not mean that photos taken through decent quality coated glass are going to be tinted one colour or another.
Lens coatings have two drawbacks. First, they must be kept scrupulously clean at all times, as oils and dirt interfere with the way they work. Fingerprints are
extremely obvious on coated glass. Second, many lens coatings are fairly fragile and are easily scratched, so care is required in handling and cleaning them. Some
lens and filters include hardened surfaces over the top of the coatings to protect them, but this is not universal.
What do “aspheric” or “aspherical” mean?
The glass elements which make up a traditional camera lens can be thought of as cross-sections of a large sphere. That is to say that the curvature of each surface is
even. The problem with spherical lens designs is that light passing through the outer edges of curved camera lenses focus at different points from light passing
through the centre. This causes focus errors, or spherical aberration and other forms of optical problems. Spherical lenses work fine if the recording surface is also
spherical (eg: the human eyeball), but in the case of cameras it’s not - the film surface or image chip surface is always flat.
One way to fix the problem is to add additional lens elements to correct for the aberration. A generally more efficient way to fix it is to make a lens element which is
not a sphere in cross section. In other words the curvature of the lens varies from the middle to the edges. Such an aspherical lens element can help simplify lens
design by minimizing the number of elements required and can result in a sharper image. Aspherical elements are particularly useful for correcting distortion in
wide-angle lenses.
There are three basic ways to make an aspherical element. The expensive way is to grind a piece of glass down to the right shape. This is quite difficult owing to the
extreme precision required to achieve the complex geometry, and so only some L series lenses use ground aspherical elements in Canon’s lens lineup. Another way is
to mould a glass lens element. Such glass moulded aspherical lens elements are used in a number of Canon’s less expensive lenses. The cheapest way is to cement a
plastic resin aspheric surface to the top of a glass spherical element. Such lenses are known as replicated aspherical elements and are particularly common among
point and shoot cameras.
Note that some lensmakers, particularly Sigma, use the terms “aspherical” or “ASPH” as marketing labels. However many modern lenses made by other makers
such as Canon also employ aspherical elements - they simply don’t advertise this fact on the outside of the lens. It’s important to remember that lenses with
aspherical elements are not automatically and intrinsically better than lenses without. Sometimes they are, though this is usually for a variety of other factors, not
merely the fact that they use aspherical elements.
What is low dispersion glass?
Low dispersion glass and its variants - ultra-low dispersion (UD) glass, extra-low dispersion (ED) glass - is expensive optical glass which can reduce unwanted colour
fringing and other optical problems in lenses, particularly long telephoto lenses.
Dispersion is the rainbow effect seen with prisms and the like - white light being split up into a rainbow spectrum of its constituent wavelengths. Low dispersion glass
does not disperse white light as much as regular glass, thereby reducing the amount of correction required to compensate for the phenomenon.
What is fluorite?
Technically, calcium fluorite isn’t glass. It’s actually a type of crystal produced synthetically by Canon and used in many of their top of the line L series lenses in
place of low dispersion glass. It’s an expensive material but is extremely useful for minimizing optical lens aberrations, particularly with telephoto lenses.
What are diffractive optics (DO)?
DO lenses contain a new type of lens element unique to Canon’s product lineup. Such lens elements, multi-layer diffractive elements, are nearly flat lens elements
with extremely fine grooves etched into them. They exploit the principles of optical diffraction rather than optical refraction.
The advantage of such DO elements is that they do a very good job of reducing chromatic aberration (colour fringing), a particularly significant problem in long
telephoto lenses. They can also be made much lighter than regular low-dispersion or fluorite lens elements, thereby shortening the length and reducing the weight of a
large telephoto lens considerably.
Unfortunately, lenses with DO elements are at present quite expensive, and have some issues with lens flare under some lighting conditions. Canon DO lenses, while
professional products, are not sold as L lenses and are marked by a pale green stripe around the end of the lens rather than a red one.
What is rear or internal focussing?
Many lenses become physically longer or shorter when you adjust focus. In other words they have two nested tubes which telescope in and out as you rotate the focus
ring. This design, while inexpensive to make, is generally undesirable because when a lens extends or contracts there will always be air and dust sucked inside it. And
inevitably this yields a bit of dust buildup over years of use.
Many Canon lenses use rear focusing (RF) or internal focussing (IF) instead. In rear focussing the lens elements closest to the camera move back and forth when you
focus but the frontmost elements do not. In internal focussing some glass elements inside the lens move within the lens barrel. In both cases the lens does not change
length at all because all lens element motion is contained within the lens barrel.
Another advantage of rear and internal focussing is that the end of the lens does not rotate during focussing. Many lenses which extend when you focus also rotate,
which can be a nuisance if you use polarizing filters or graduated neutral density filters
Why doesn’t my camera just come with a lens? Isn’t that kind of cheap?
No. It’s actually a good thing. First of all, the whole point of a camera with interchangeable lenses is you can attach whatever lens you need. Unlike a simple point and
shoot with its non-removable lens you aren’t limited to whatever the manufacturer builds into the camera. Second, everyone has different needs and budgets. So it’s
usually desirable not to include a lens so you can choose the lens or lenses which are right for you, not some generic lens. Third, what if you were to buy another
camera? Then you would have two of the same lenses.
Having said that, Canon do sell many EOS cameras bundled with included lenses. Such lenses are called kit lenses, but frankly not all kit lenses are of a particularly
high quality. You’re often best off buying the camera body which suits your needs and finding a good lens to match it.
What are wide-angle, normal and telephoto lenses?
We’ve all had the experience before. You’re trying to take a photograph of some friends, but you just can’t fit everybody into the picture. You step backwards further,
but there’s a wall or cliff or something, and it just isn’t going to work, so you tell your friends to squeeze in closer. Or you see a bird flying by in the distance, you grab
your camera, and you end up with a big photograph of sky with a disappointingly tiny little dot in the middle of the frame.
In each case the field of view provided by the lens isn’t appropriate for your subject matter. In the first instance your lens is not “wide” enough to take in the whole
scene, and in the second your lens isn’t “long” enough. There are three rough categories of lenses when it comes to how much of a scene they can take in, and the
field of view of each type is defined by an optical property known as the focal length of the lens (a property explained later in this document).
• A so-called normal lens roughly approximates the perspective, though not the area of, a scene seen by one human eye. By convention a normal lens on a
35mm film camera (and thus a full-frame EOS digital SLR) has a focal length of 50mm or so. Think of normal lenses as being good for taking pictures in close, but not
intimate, proximity to a subject, like a waist-up picture of a person in an ordinary room.
• A wide-angle lens can take in a large area of a scene. This has two common applications - first, it means you can take in sweeping panoramic landscape
scenes, and second, you can take in large areas of an ordinary room. If you want to take a photo of a group of friends at a dinner party you’ll need a wide angle lens
unless you can back up far enough to get everyone in. On a 35mm film camera a wide angle lens would have a focal length of, say, 35mm or less.
• Looking through a telephoto lens is like using a telescope - it narrows down what can be seen in a scene or makes the subject seem much closer than it
really is. A telephoto lens might have a focal length of 70mm or more on a 35mm camera.
Note one area of potential confusion - there are different measurements expressed here in millimeters, but which refer to two different physical properties. In the
case of 35mm film cameras, we’re talking about the width of the film material. But in the case of, say, an 80mm lens, we’re talking about its focal length. You can thus
put a 28mm lens on a 35mm camera - the measurements are about different things.
These are just broad categories, of course, and there are big variations in each one. You can get an inexpensive 28mm lens, for example, which is only modestly wide.
Or you can get a crazy expensive 14mm lens which can take in a huge area of a scene - perfect for shots of ultra-dramatic skies. Similarly you could put an 85mm lens
on your camera for portrait photography, or you could sell your car and buy a huge 600mm lens that requires a large suitcase for transportation but which lets you
take a closeup of a bird’s face from a huge distance away.
What’s the difference between a zoom lens and a fixed focal length (prime) lens?
A prime lens is a lens in which the field of view (focal length) cannot be adjusted. The only way to take in more or less of the scene is to walk closer to or further from
the subject. (Sometimes called “zoom with your feet,” though this is technically inaccurate since changing camera position is not the same thing as adjusting the focal
length) Or you have to carry a selection of lenses of different focal lengths with you and swap them out as required.
A zoom lens is a lens in which the field of view can be adjusted. If you can’t fit in all your friends in the picture, for example, you could just rotate the zoom ring on the
lens until they’re all in there. Or if that bird is too far away you could rotate it the other way to zoom in closer.
Up until the late 1980s prime lenses were the most common lens sold, because from an optical design standpoint it’s much easier to design a high quality prime lens
that can take nice sharp photographs than a decent quality zoom lens. But a prime is also obviously a lot less convenient, since you have to move around more to fit
stuff in. So by the late 80s zoom lenses became more and more popular. Today hardly any low-cost lenses are prime lenses, because everybody wants zooms.
So why buy a prime lens at all? Well, for the same reason as ever - prime lenses are easier to build and offer fewer compromises in design. If you want a really sharp
crisp lens, then a good prime will offer sharper pictures than most zooms. Or if you want a lens that can let in lots of light and thus can be used for low-light
photography then you’ll probably want a prime, since it’s much harder to build a “fast” (lets in lots of light) zoom lens. And some crusty old photographers also argue
that using prime lenses is very important for novice photographers since it forces them to learn about the importance of focal lengths and perspective.
Lens construction is thus always about tradeoffs. You may want a lens that’s small, lightweight, has zoom capabilities, lets in lots of light, is really sharp, has high
contrast, doesn’t distort the image and is cheap. But in real life you can only get some of those properties - it’s impossible to get all of them, sadly.
Most amateurs on a budget choose the flexibility of low-cost zoom lenses over picture quality as their compromise. Many advanced amateurs choose the higher
picture quality of affordable primes and deal with the inconvenience as theirs. And many professionals buy high quality zooms that weigh a ton and cost piles of money
as theirs.
Note one common misconception - a lot of people think zoom lenses are used for taking photos of things far away. That’s actually a better description of a telephoto
lens, as described above.
Which lens should I buy for my camera?
As with buying a camera there are a lot of things to consider, so this question really can’t be asked without asking many more questions first. Here are some of them:
What exactly are you going to be photographing?
Your photographic goals and objectives essentially inform all of the other decisions. Will you being shooting landscapes? Portraits? Your kids or pets? Flowers? Wild
birds? Sports? Architecture? Will you be doing travel photography? Will you be hiking with your gear? These sorts of questions are critical to ask yourself first.
How much money do you want to spend?
You can spend huge amounts of money on lenses, so determining your budget, as with cameras, is pretty important.
Do you want to buy a used or a new lens?
The same questions apply as when purchasing a new or used camera.
Do you want a prime (fixed focal length) or a zoom (variable focal length) lens?
Prime lenses generally afford higher optical quality than zooms, except in the case of really expensive pro zoom lenses. However prime lenses mean you have to walk
around more - you can’t simply adjust the zoom setting to get the framing you need.
What focal length or focal length range do you want to cover?
I’d sit down with your photos and think about what focal lengths you tend to use most and where there are gaps. Maybe you want an extreme wide angle, for example.
If so there’s no point getting another telephoto.
Do you need a fast lens?
Do you want to do low-light photography without a tripod or flash? Do you want to do portrait photos while blurring the background? These applications call for a
faster lens which can let in more light.
Do you want to buy Canon-built or third party lenses?
Third party makers build many great lenses, but many are also really poor - you have to do some research. And others have compatibility problems with existing
cameras or may have future compatibility problems. Are the price savings worth it for the specific lens you’re interested in?
Do you care about the user interface and build quality?
A lens may be slow to focus or inconvenient to use but offers higher optical quality than another lens with a faster motor and a better designed UI. Ring USM motors
are fast, silent and offer full-time manual override, but lenses containing such motors tend to cost more than slower, noisier non-FTM arc-form (AFD) motors.
What aspect of optical quality is important to you?
Obviously sharpness and contrast are pretty important to most people, but what about distortion? Many consumer zooms have a lot of distortion, making them
unsuitable for architectural photography. They also tend to be more vulnerable to flare (lowering contrast or resulting in bright spots on the picture if a bright light like
the sun is in or near the frame) and tend to have very slow maximum apertures.
Which lens should I buy for my EOS digital camera?
There are two things that are important to keep in mind when shopping for lenses for an EOS digital camera, such as the EOS 10D, rather than an EOS film camera.
First, EOS digitals are still not as cheap as film cameras, so don’t just try to find the cheapest lens you can. And if you’re going to be shelling out this much money for
the camera body, buying the cheapest lens you can find is not merely false economy, it’s downright foolish, if you ask me.
It’s like spending massive amounts of money on a high-end CD player and amplifier and then plugging them into a pair of toy loudspeakers. Just as the final sound of
your music will be hobbled by the toy loudspeakers the final quality of your pictures will be hobbled by a cheap lens. So avoid lenses in the “cheapie” category (see
below).
Second, with the exception of the cropping factor the selection criteria for buying a lens for a digital camera really don’t differ much from the criteria for buying a lens
for a film camera. What type of photography do you want to do? Do you need a wide angle for landscapes? A fast-focusing telephoto for sports? A sharp and short
telephoto for portraits? How much weight do you want to carry around? These questions are the same regardless of whether you want to shoot film or digital - check
the list above.
But as noted, there is one major difference to keep in mind with most digital EOS cameras - the cropping factor, also known as the focal length multiplier. With the
exception of the EOS 1Ds, 1Ds mark II and 5D, which have full-size image sensors equivalent in size to a 35mm EOS film camera, most current EOS digital cameras
use image sensors smaller than a 35mm film frame. If your camera has a cropping factor of 1.6x it means that, say, a lens with a 50mm focal length will suddenly
behave rather like a lens with an 80mm focal length. The focal length of the lens does not change, but its apparent effect does. (since the image sensor is smaller,
think of it as simply snipping off all four sides with a pair of scissors, resulting in a smaller picture, and then enlarging the picture on a photocopier)
This issue has two nice advantages. First, you can buy a cheap 50mm lens and use it as a very nice portrait lens. Second, you can attach a telephoto to your camera
and it’ll behave like a much longer telephoto - you’ll have much more reach. The drawback, of course, is that wide angle pictures are harder to achieve as you need
much wider lenses for such photos. This can be a significant problem for many people.
So with such digital cameras you will probably want to get a lens that’s a bit wider than you would if you were buying for a 35mm film camera. If you use a 28-105mm
lens on your 35mm camera, for example, you might get a 24-85mm lens instead.
The one question related to this is whether the EF-S 18-55 lens (see next section) included with the EOS 300D/Digital Rebel/Kiss Digital kit is worth it. The
consensus is that it’s definitely worth the small increase in price over the body only. The EF-S 18-55 is no L series lens by a long shot, but it offers surprisingly decent
optical quality for the incredibly low price, and it’s the only affordable way to get down to moderately wide angles (roughly the same as a 29mm lens on a 35mm film
camera) on the 300D.
One final issue with digital is that some newer lenses have coatings which work a bit better with digital image sensors than those used on older lenses. Generally
speaking this is a fairly subtle issue, advertising notwithstanding.
What is an EF-S lens?
From essentially the introduction of the EOS camera system in 1987 through to 2003 Canon standardized on a single lens mount system for all of their SLR cameras -
the EF (electro focus) lens mount. So throughout this time there was no possible source of confusion, since all EF lenses made by Canon and other lens makers will
physically fit all Canon EOS cameras.
However, in 2003 Canon introduced a new digital camera, the consumer-oriented EOS 300D/Digital Rebel/Kiss Digital camera, which sported a new lens mount
design dubbed EF-S. All consumer to midrange digital EOS cameras released since have been both EF and EF-S compatible. For reasons explained in a moment, no
film camera has ever been EF-S compatible.
So it’s important to remember that digital camera bodies with EF-S lens mounts are totally compatible with all regular EF lenses. However an EF-S lens can fit only
EF-S compatible cameras and no others. (unless the lens is altered - see the section on hacking below).
EF-S bodies have small mirror boxes - roughly 2/3 the size of a regular EOS camera (also known as a 1.6x cropping factor) - because they use image sensors which
are smaller in area than 35mm film. They, and APS cameras which similarly used small imaging areas, are thus often called sub frame cameras. Cameras which use
35mm film or which use large sensors that are the same size as a frame of 35mm film are commonly called full frame cameras these days.
EF-S cameras thus support lenses with a shorter back focus distance than EF lenses, because the mirror swings further back. This is where the “S” comes from -
EF-S lenses have shorter back focus distances. (ie: the back part of the lens can get physically closer to the image sensor since the mirror is smaller) Having a
shorter back focus distance allows Canon to produce cheaper wide-angle lenses that work with the smaller image format of a sub frame digital SLR, since it’s
optically very challenging to create a wide angle lens with a long back focus distance.
Canon have a small but growing series of EF-S lenses available, ranging from inexpensive kit lenses to very good high-quality lenses with image stabilization. There’s
even a very interesting 60mm macro lens with an EF-S mount. The super wide angle EF-S 10-22mm 3.5-4.5 USM (roughly 16-35mm coverage if it were full frame) is
particularly well regarded, as is the EF-S 17-55 2.8 IS USM, which is an L lens in all but build quality and name.
The main issue to be concerned about with EF-S is the future value of the lenses. Right now full-frame image sensors are extremely expensive to make, which is why
nearly all digital SLRs out there have image sensors smaller than that of a frame of 35mm film. But in the future it’s likely that prices on such sensors will drop, at
which time full-frame digital SLRs will become more affordable and thus EF-S lenses will no longer be of use except on pre-existing cameras. The two questions are -
how long will this take and will you be able to get good use of your investment in EF-S lenses before this occurs? The first nobody knows the answer to, and the
second can only be answered by you. For the time being it seems likely that it’ll be some years before affordable full-frame sensors are ubiquitous, so EF-S lenses
aren’t necessarily a bad idea, assuming you aren’t planning on upgrading to full-frame as soon as you can.
Can my camera take EF-S lenses?
Any Canon EOS camera with a red dot on the lens mount can take EF lenses. Any Canon EOS camera with both a red dot and a white square on the lens mount can
take both EF lenses and EF-S lenses.
What you see is what you get
This whole discussion about focal lengths and EF versus EF-S can be very confusing if you’re a beginner. The key thing to remember if you’re just starting out is what
you see is what you get. When you look through the viewfinder you’re going to see pretty well exactly what will be in the photograph - minus a tiny little strip along
each edge on consumer cameras. So there’s no need to worry about mathematical calculations and whatnot to figure out what will be in your picture and what won’t.
The only time the whole cropping factor is really an issue is when you’re comparing how much of a scene (coverage angle) is taken in by an EF lens on a full-frame
camera, compared to an EF lens on a cropped body, or compared to an EF-S lens on an EF-S compatible camera. For guidance on this, take a look at my Complete
EOS Lookup Page. It allows you to compare multiple lenses to see how much of a scene each lens can take in when used on cropped or full frame bodies.
Distinguishing EF from EF-S
Regular EF bodies and lenses use raised red dots for aligning lens and body. EF-S bodies have a white square as well, which must be lined up to the white square on
EF-S lenses. Interestingly enough, EF-S lenses also have rubber rings around the end which press up against the interior of the camera body. This is not as
sophisticated as the weather seals used in L series lenses, but presumably helps reduce dust levels inside the camera slightly. Also, according to Canon, this ring
minimizes damage if you were to try and mount an EF-S lens on a EF-only camera.
Full frame equivalent
You’ll sometimes see phrases such as “full frame equivalent” or “35mm equivalent” in conjunction with lenses designed for subframe sensors, such as EF-S lenses.
Properly speaking these are not equivalent values for a variety of technical reasons, but they are nonetheless useful points of reference. For instance, a 60mm EF-S
lens has the same field of view as a 96mm lens on a 35mm film camera. So sometimes 60mm EF-S lenses are said to have a full-frame equivalent field of view of
96mm.
EF-S lenses and film cameras
No EOS 35mm film camera has or is ever going to use an imaging area smaller than 36x24mm, so no EOS 35mm film camera will ever be able to support EF-S lenses.
Even if you were to attach one somehow the mirror would collide with the back of the lens when it flipped up, and the lens would vignette severely because EF-S
lenses can’t image an image circle as large as 35mm film. In theory Canon might be able to build an APS camera with support for EF-S lenses, since APS film uses a
surface area smaller than that of 35mm film, but since APS is a commercially moribund format that isn’t ever going to happen. So the only cameras you’ll ever see
with EF-S lens mounts are going to be digital.
Hacking EF-S lenses
While EF-S lenses are not designed to fit EF-only cameras, it is possible to saw off or, in some cases, unscrew the back of an EF-S lens and attach the lens to any
EOS camera. The problem is that if you put a modified EF-S lens on an EOS camera with a standard sized mirror box then the mirror will flip up and smash into the
lens when you try to take a photo. So modified EF-S lenses will only work with older EOS digital cameras with cropping factors of 1.6x that predate the EF-S system:
namely the EOS D30, D60 and 10D. Even then there are risks. For example, at its widest position the EF-S 10-22mm lens collides with the mirror in non-EF-S
compatible cameras, even those with small mirror boxes. (for this reason it’s unwise to use a modified EF-S lens on a 1.3x digital camera such as the 1D) Messing
around in this fashion is fun - I’ve done it myself and it works well - but obviously invalidates your Canon warranty and runs the risk of breaking something.
What are all these numbers printed on my lens?
Lenses have bits of text printed on the barrel or around the front element which convey a lot of important information about their properties. Be really careful when
shopping for lenses. Two lenses may have very similar-looking names, but may actually be completely different one from the other.
Here are two examples. Note that all the technical terms used here are described later on in this FAQ.
CANON LENS EF 28-80mm 1:3.5-5.6. Ø58mm.
EF means that the lens is of the Canon EF type. EF lenses fit Canon EOS cameras and virtually no others.
28-80mm refers to the focal length of the lens. In this case there are two values since the lens is a zoom lens which can go from 28mm at its widest to 80mm at its
longest. These numeric values in millimeters essentially indicate the coverage area of the lens.
1:3.5-5.6 refers to the widest aperture of which the lens is capable. The 1: is there since f/stops are, technically speaking, ratios. Since the lens is a zoom there are two
aperture values - f/3.5 and f/5.6. This particular lens is an inexpensive amateur lens which can be opened up to f/3.5 at the widest end (28mm) but only f/5.6 at the
longest end (80mm). This means it’s a fairly slow lens - it can’t let in much light, even when its aperture diaphragm is fully open.
Note that the autofocus motor type is not indicated, which means that the lens uses either an AFD (arc-form drive) or micromotor drive. Both types are slow and noisy
compared to ultrasonic (USM) motors.
Ø58mm refers to the filter ring diameter. In other words, screw-on filters 58mm in diameter will fit this lens.
CANON LENS EF 200mm 1:2.8L II USM. Ø72mm.
EF means that the lens is a Canon EF lens for EOS cameras.
200mm refers to the focal length. Since only one value is indicated, this lens is a prime lens (ie: a lens with a fixed focal length).
1:2.8 refers to the widest aperture of which the lens is capable. f/2.8 is reasonably wide, especially for a 200mm telephoto lens, and so this is considered a fast lens.
L indicates that the lens is an L or “luxury” series Canon lens. Such lenses are generally the best that Canon manufacture. They are marked with a characteristic red
stripe around the end of the lens barrel.
II indicates that this is the second version of this lens with these particular numerical specifications that Canon have made.
USM refers to the autofocus motor type used by the lens. In this case it uses an ultrasonic motor - see below. Non-L USM lenses are marked with a characteristic
gold stripe around the end of the lens barrel. L lenses usually have USM motors, but have a red stripe instead (ie: the red stripe takes priority and you don’t see
lenses with two stripes).
Ø72mm refers to the filter ring diameter. In other words, screw-on filters 72mm in diameter will fit this lens, making it a fairly large lens.
What is a Canon L-series lens and why is it a big deal?
Canon sell a number of lenses in a special series they refer to as L for “luxury.” These are their most expensive and highest-quality lenses, and are readily
identifiable by the red stripe painted around the end of the barrel.
L series lenses offer higher optical quality than their non-L equivalents, and have an important technical aspect in common. At least one element in every L lens is
either made of fluorite crystal rather than glass, is a ground aspheric lens element (not a moulded/replicated aspheric lens as used in less expensive lenses) or is
made from ultra-low dispersion glass. Most L series lenses are also sturdily built - many are encased in metal barrels and are weatherproofed - and most are very
fast lenses for their focal lengths. Nearly all telephoto L series lenses are also off-white rather than black.
These lenses are, therefore, marketed as professional camera lenses and are usually priced out of the range of most consumers. They can be used to take great
photographs, but the cost, weight and size of these lenses are the tradeoffs.
Of course, a lens doesn’t have to be an L series lens to take good pictures. Many EOS lenses offer excellent optical quality - they just don’t need and thus don’t have
exotic fluorite lens elements and so on. Many of Canon’s prime lenses in the 35mm to 135mm range fit in this category - see below. And some recent EF-S lenses
offer near-L image quality but lack the red ring and the tough build quality of contemporary L series lenses.
Note also that the presence of a red ring around the end of a lens barrel only indicates an L series lens if it’s actually made by Canon. Some other makers happily
paint red stripes around the end of their lenses too, but this in no way guarantees that the lens meets the quality standard of a Canon L lens.
What other general categories of Canon EOS-compatible lenses are there?
In addition to the aforementioned L series lenses most other Canon EF lenses fall into a number of broad categories. Note, however, that these are not official
Canon-named categories. As far as Canon is concerned, EF lenses come in two categories - L and all the rest. Nonetheless these informal categories are useful to
keep in mind when lens shopping.
Category 1 - consumer lenses.
At the bottom of the consumer line are the cheapies - ultra-low cost, low-quality, slow lenses with plastic mounts and no distance scales. Most of the kit lenses - 28-80
and 28-90 lenses with typical aperture ranges of 4.0 to 5.6 - fit into this category. These lenses are built to be sold as inexpensively as possible and don’t have very
good optical quality. The only exception to this basic rule is the 50mm 1.8 II - plastic lens mount - which has excellent optical quality despite its cheap build quality,
because it isn’t a zoom lens like all the others. The cheapies are easily recognizable by their all-plastic construction and straight, parallel-sided lens barrels. Most of
the late-model cheapies are identified by the silver (chrome) ring around the end.
Am I being a huge snob by calling them “cheapies”? Maybe, but the point is that Canon optimize these lenses for cheapness. They want products to sell in massive
numbers in shopping mall/high street camera shops and department stores. This market does not, it seems, place a great deal of value on image quality - cheap prices
for impulse buys are everything. That’s great for Canon’s balance sheet, but frankly, if I’m going to be dealing with the hassle of carrying around an SLR camera I
want at least half-decent optical quality for the attached lens. Otherwise I think it’s a lot easier just to carry around a cheap lightweight point and shoot camera.
Category 2 - midrange zooms.
In the midrange are better lenses with improved optics, sturdier build quality, metal mounts and distance scales. These often have ring USM motors. The 24-85
3.5-4.5 USM, 28-105 3.5-4.5 USM and 100-300 4.5-5.6 USM are typical examples. They’re decent consumer lenses but don’t have the optical clarity of the pro
lenses, especially when shooting wide open. However, they generally cost a fraction of the price of the top of the line stuff. These lenses are generally fairly elegantly
designed, with slightly rounded and tapered lens barrels, and usually have easy to grip ribbed rubber zoom rings rather than bare plastic.
There are also older low-end zooms with decent optical quality, such as the 28-70 3.5-4.5 II, which don’t use modern USM drives but which nonetheless offer good
value for money on the used market.
Category 3 - inexpensive primes.
Canon also sell and have sold a number of prime (ie: non zoom) lenses with acceptable optics and average build quality (usually with noisy motor drives, metal mounts
and distance scales), such as the 28mm 2.8 and 50mm 1.8 (metal lens mount). Despite their low cost and pretty unremarkable construction they can provide quite good
photographic results.
All lenses in this category are mostly normal or near normal lenses - no super wide angles and no long telephotos. The designs generally date back to the early days
of the EOS lineup, so they tend to look a bit old-fashioned, style-wise. Canon just haven’t seen the need to update any of them.
Category 4 - good primes.
This is a group of prime lenses which offer excellent optics and decent build quality, but which don’t really need and thus don’t use ultra low-dispersion glass or
calcium fluorite crystals or other hallmarks of L-class lenses. Remarkably good lenses like the 85mm 1.8 and the 100mm 2.8 macro fit into this category. Most have
ring ultrasonic motors. They generally resemble the category 2 lenses - slightly rounded and tapered lens barrels. Optically they are professional lenses in all but the
name, though they’re usually not quite as heavy-duty as the fancier L lenses.
Category 5 - specialized lenses.
Canon also make a handful of expensive specialized lenses for unusual applications which I’ll just lump into this category for lack of anywhere else to put them. These
include their tilt-shift TS-E lenses, the MP-E 65mm super-macro lens and the DO (diffractive optics) lenses.
Which lens falls in which category?
Here’s a list of most Canon EOS-compatible lenses - both current and discontinued - sorted according to the categories above. Lenses are EF lenses (all EOS
cameras) except those marked EF-S, which fit only EF-S-compatible digital EOS cameras.
The numeric value marked with the Ø symbol is the filter mount diameter. In other words, round screwmount filters of the size indicated can be attached to this lens. A
few lenses - the extreme wide-angle lenses and the really long telephotos - use drop-in or gelatine filters inserted into the lens barrel.
Many lenses have the word “Macro” marked on them but only those identified here as macro are true macro lenses. True macro lenses are defined as those lenses
capable of 1:1 focussing or better. The only Canon macro lens which doesn’t quite fit this definition is the 50mm 2.5 Compact Macro, which requires the add-on
Life-Size adapter to reach 1:1.
Check out Canon’s Camera Museum site for technical details on all the EF lenses that Canon has ever produced.
Category 1 - cheapies.
These inexpensive lenses feature all-plastic barrel construction with plastic lens mounts (the 75-300 series and the 28-200 lenses being exceptions - they have metal
mounts) and no distance scales. Those lenses in this category which have ultrasonic motors (USM) use cheaper micromotor USM, not ring USM. USM lenses are
marked with a striped gold line around the end. Some of these lenses also have silver (chrome) rings around the end for good looks. Most lenses in this category
support optional manual focussing, but their manual focus rings are usually awkward and cumbersome to use.
EF-S 18-55 3.5-5.6, Ø58
Inexpensive EF-S kit lens; reasonable optical quality
EF-S 18-55 3.5-5.6 USM, Ø58
Apparently only sold in Japan
EF-S 18-55 3.5-5.6 II, Ø58
Cosmetic update to the above
22-55mm 4.0-5.6 USM, Ø58
28-105mm 4.0-5.6, Ø58
28-105mm 4.0-5.6 USM, Ø58
28-80mm 3.5-5.6, Ø58
28-200mm 3.5-5.6, Ø72
28-200mm 3.5-5.6 USM, Ø72
28-80mm 3.5-5.6, Ø58
28-80mm 3.5-5.6 II, Ø58
28-80mm 3.5-5.6 II USM, Ø58
28-80mm 3.5-5.6 III, Ø58
28-80mm 3.5-5.6 III USM, Ø58
28-80mm 3.5-5.6 IV USM, Ø58
28-80mm 3.5-5.6 V USM, Ø58
28-90mm 4-5.6, Ø58
28-90mm 4-5.6 USM, Ø58
28-90mm 4-5.6 II, Ø58
28-90mm 4-5.6 USM II, Ø58
Silver-coloured
35-70mm 3.5-4.5 A, Ø52
Autofocus only - no manual focus ring
35-80mm 4-5.6, Ø52
35-80mm 4-5.6 PZ, Ø52
Powered (motorized) zoom
35-80mm 4-5.6 II, Ø52
35-80mm 4-5.6 III, Ø52
35-80mm 4-5.6 USM, Ø52
35-105mm 4.5-5.6 USM, Ø58
38-76mm 4.5-5.6, Ø52
55-200mm 4.5-5.6 USM, Ø52
55-200mm 4.5-5.6 II USM, Ø52
75-300mm 4-5.6, Ø58
75-300mm 4-5.6, Ø58
75-300mm 4-5.6 II, Ø58
75-300mm 4-5.6 II USM, Ø58
75-300mm 4-5.6 III, Ø58
75-300mm 4-5.6 III USM, Ø58
75-300mm 4-5.6 USM, Ø58
80-200mm 4.5-5.6, Ø52
80-200mm 4.5-5.6 II, Ø52
80-200mm 4.5-5.6 USM, Ø52
90-300mm 4.5-5.6, Ø58
90-300mm 4.5-5.6 USM, Ø58
100-200mm 4.5 A, Ø58
Autofocus only - no manual focus ring
Category 2 - midrange zooms.
All lenses in this category have metal lens mounts, and come in two basic flavours - old-style lens barrel and new style. The old style feature hard textured plastic
barrels with narrow focus rings and their AF/MF switches are low and sometimes difficult to adjust. The new style feature slightly more resilient shiny plastic with
wider focus and zoom rings, often with lots of easy-grip ribbed rubber. The new style lenses also boast ring USM focus drives and easier to operate AF/MF switches.
EF-S 10-22mm 3.5-4.5 USM, Ø77
Unusually for a lens not marketed as L series, this lens contains a Super UD element and has very good image quality.
EF-S 17-85mm 4-5.6 IS USM, Ø67
EF-S 17-55 2.8 IS USM, Ø77
This is an interesting lens since it actually has L-series image quality thanks in part to the use of UD glass. However, build quality is on par with better consumer
lenses and not L series lenses.
20-35mm 3.5-4.5 USM, Ø77
24-85mm 3.5-4.5 USM, Ø67
Available in silver or black
28-70mm 3.5-4.5, Ø52
28-70mm 3.5-4.5 II, Ø52
28-80mm 3.5-5.6 USM, Ø58
(unlike later all-plastic II and higher models, these lenses have a metal mount)
28-105mm 3.5-4.5 “Macro” USM, Ø58
28-105mm 3.5-4.5 II “Macro” USM, Ø58
28-135mm 3.5-5.6 IS “Macro” USM, Ø72
35-70mm 3.5-4.5, Ø52
Old-style barrel
35-105mm 3.5-4.5 “Macro”, Ø58
Old-style barrel, push-pull zoom
35-135mm 4-5.6 USM, Ø58
50-200mm 3.5-4.5, Ø58
Old-style barrel
70-210mm 3.5-4.5 USM, Ø58
70-210mm 4 “Macro”, Ø58
Old-style barrel, push-pull zoom
70-300mm 4-5.6 IS USM, Ø58
The replacement to the 75-300 4-5.6 IS USM
75-300mm 4-5.6 IS USM, Ø58
Optically a cheapie, but image stabilization moves it up a category
100-300mm 4.5-5.6 USM, Ø58
100-300mm 5.6 “Macro”, Ø58
Old-style barrel, push-pull zoom
Category 3 - inexpensive primes.
With the exception of the all-plastic (including plastic lens mount) 50mm 1.8 mark II, the inexpensive primes all have old-style lens barrels - hard textured plastic, a
narrow focussing ring and distance scale.
28mm 2.8, Ø52
35mm 2, Ø52
50mm 1.8, Ø52
50mm 1.8 II, Ø52
Plastic lens mount, no distance scale but same good optics as the 50mm 1.8
Category 4 - good primes.
As with the midrange zoom lenses, the good primes are available in either old-style lens barrel designs or new-style.
15mm 2.8 fisheye
Old-style barrel
20mm 2.8 USM, Ø72
New-style barrel
24mm 2.8, Ø58
Old-style barrel
28mm 1.8 USM, Ø58
New-style barrel
50mm 1.4 USM, Ø58
New-style barrel
50mm 2.5 Compact macro, Ø52
True (1:2; 1:1 with adapter) macro, old-style barrel
EF-S 60mm 2.8 USM macro, Ø52
EF-S only true 1:1 macro lens
85mm 1.8 USM, Ø58
New-style barrel
100mm 2 USM, Ø58
New-style barrel - do not confuse with the 100mm 2.8, which is a macro lens
100mm 2.8 Macro, Ø52
True 1:1 macro, old-style barrel
100mm 2.8 Macro USM, Ø58
True 1:1 macro, new-style barrel
135mm 2.8 SF, Ø52
Old-style barrel, adjustable soft focus control
Category 5 - specialized lenses.
Unusual, expensive and specialized lenses.
MP-E 65mm 2.8 1-5x Macro
Powerful macro lens, for closeups only
TS-E 24mm 3.5 L, Ø72
Tilt-shift, manual focus only
TS-E 45mm 2.8, Ø72
Tilt-shift, manual focus only
TS-E 90mm 2.8, 58
Tilt-shift, manual focus only
EF 70-300 4.5-5.6 DO IS USM
Diffractive optics. Marked with a green ring
EF 400mm 4 DO IS USM
Diffractive optics. Marked with a green ring
L series lenses
All L series lenses are easily identifiable by the red ring around the end of the barrel and the letter L at the end of their technical designations.
Most L series lenses are heavy shiny black plastic or white-painted metal. Most newer lenses (since 1999 or so) are weather-sealed though some (the earliest L
series) are textured black plastic. The handful of early L series lenses with old-style barrels are not built to the same tough build quality of modern L lenses, though
optically they’re fine.
Most L series lenses are large and fast lenses and thus quite expensive. However in the past few years Canon have also released a few more affordable L series
zooms. These lenses are optically slower f/4 lenses which are smaller, lighter and cheaper than their f/2.8 counterparts. No L series lens has ever been made with an
EF-S lens mount: they are always EF lens mounts only.
14mm 2.8 L USM
24mm 1.4L USM
16-35mm 2.8 L USM, Ø77
16-35mm 2.8 L II USM, Ø82
17-35mm 2.8 L USM, Ø77
17-40mm 4 L USM, Ø77
20-35mm 2.8 L, Ø72
24-70mm 2.8 L USM, Ø77
24-105mm 4 L IS USM, Ø77
28-70mm 2.8 L USM “Macro”, Ø77
28-80mm 2.8-4 L USM, Ø72
28-300mm 3.5-5.6L IS USM, Ø77
35mm 1.4 L USM, Ø72
35-350mm 3.5-5.6 L USM, Ø72
50mm 1 L USM, Ø72
50mm 1.2 L USM, Ø72
50-200mm 3.5-4.5 L, Ø58
Old-style barrel, push-pull zoom
70-200mm 2.8 L USM, Ø77
70-200mm 2.8 L IS USM, Ø77
70-200mm 4 L USM, Ø67
70-200mm 4 L IS USM, Ø67
80-200mm 2.8L
Old-style barrel; not compatible with teleconverters
85mm 1.2 L USM, Ø72
85mm 1.2 L USM II, Ø72
100-300mm 5.6 L, Ø58
Old-style barrel, push-pull zoom
100-400mm 4.5-5.6 L IS USM, Ø77
Push-pull zoom
135mm 2 L USM, Ø72
180mm 3.5 Macro L USM, Ø72
True 1:1 macro
200mm 1.8 L USM
200mm 2.8 L USM, Ø72
200mm 2.8 L II USM, Ø72
300mm 2.8 L USM
300mm 2.8 L IS USM
300mm 4 L USM, Ø77
300mm 4 L IS USM, Ø77
400mm 2.8 L USM
400mm 2.8 L II USM
400mm 2.8L L IS USM
400mm 5.6L USM
500mm 4 L IS USM
500mm 4.5 L USM
600mm 4 L USM
600mm 4 L USM II
1200mm 5.6L USM
What’s wrong with the “kit” lens included with my camera? Why do you call it a cheapie?
Don’t take it personally. Canon sell most of their inexpensive consumer cameras either as camera bodies alone with no lenses or as complete kits with a cheap lens,
camera strap and perhaps other accessories included. Such kits are usually aggressively priced, and most consumers go for them since they’re convenient and the
supplied lenses are so cheap. The included lenses are usually referred to as “kit lenses,” though they can also be purchased separately if you like.
Unfortunately, kit lenses for low-end cameras are optimized for cheapness, as noted above. They aren’t engineered to offer the best optical quality you can find. This
means they’re usually not terribly sharp and they also tend to produce somewhat low-contrast photos. Kit lenses are also considerably less rugged than more
expensive lenses. Finally they’re always very slow lenses and so are not much good in low-light situations. These drawbacks are also the case, to varying degrees, for
kit lenses made by every manufacturer, incidentally, not just Canon.
Of course, a cheap kit lens will take better photos than a lens you can’t afford and thus don’t have. Particularly if you avoid shooting wide open and use an aperture
setting like f/8 to maximize sharpness. Nonetheless, you don’t have to settle for poor quality if you check out the used market or if you’re willing to pay a little extra -
see the section after next for details.
Why are quality lenses so expensive?
Lenses are very complex and costly products to design and manufacture. Each component has to be built to incredibly tight tolerances and carefully assembled. The
extremely pure optical-grade glass used in making lenses is very expensive to produce. Expensive lenses don’t have the volume sales of cheap lenses, making them
more expensive still to produce profitably. So, unfortunately, when it comes to lenses you generally get what you pay for.
Lenses going for 200-300 US$ or € may seem very expensive to a novice, but they are in fact considered dirt cheap lenses by professionals. This isn’t snobby elitism
necessarily - it’s just how it is. Lenses with high optical quality usually cost a lot of money. Photography is, unfortunately, a fairly expensive endeavour.
What’s a good beginner lens?
This really depends on your photographic goals. Here are some possibilities to consider.
But before you rush out and buy a lens based on these suggestions I strongly recommend trying out the lenses you’re interested in before you buy. Most decent
stores won’t mind if you go in with your camera and roll of film or an empty memory card and take a few shots of the shop using a couple of lenses. (be sure to use a
tripod or rest the camera on a sturdy surface and use identical settings for each lens) They might grumble a bit, but how else can you decide whether a given lens is
good for you? Certainly you don’t want to be trusting the advice of random people on the Internet!
Cheap prime lens.
If your primary objective is to learn more about basic photography skills and take photos of reasonable quality then your first lens should probably be a Canon 50mm
1.8 lens. This is a very fast fixed focal length lens. But since it’s technically easy to build a 50mm lens, it’s also astoundingly cheap. New Canon 50mm 1.8 mark II
lenses can be bought for as little as $75 US.
Such a lens, while cheap, takes sharp clear photos and can be used in extremely dim environments without the harsh light of a flash because it’s so fast. So the photos
you take with it will look better than those from a typical point and shoot both because they’re sharp and because you’re not bathing your photos in ugly glaring light
from a camera’s built-in flash. Natural light photographs almost always look better than on-camera flash.
Of course, since it’s a prime lens you will have to walk around more to get a lot of shots framed right. And some wide-angle or telephoto-type shots you won’t be able
to get at all, so those are the obvious disadvantages.
Note that Canon have made two versions of the 50mm 1.8 lens. The older lens has no Roman numeral designation and has a metal mount, a distance scale and an
optional clip-on hood. The mark II version has a plastic mount, no distance scale and a clumsy screw-on optional hood. If you can find an original lens it’s probably
worth going for - it costs as much used as the mark II does new, but is of slightly tougher build quality. Optically the two lenses are basically identical. Canon also sell
the 50mm 1.4 USM, which is optically a bit faster and uses a USM drive with FTM, but it costs considerably more than the 50mm 1.8.
However, if you use a digital camera with a cropped sensor (basically any EOS digital camera except for a few top models) then the 50mm might be a less useful
choice, since it essentially behaves like a longer telephoto on such models, and won’t let you get in much of a scene. In such cases a 28mm 2.8 might be a better
option.
Cheap zoom lens.
If you value convenience and image quality is not a priority then an inexpensive zoom lens, such as the kit lenses sold with consumer-level cameras, is fine. However I
don’t recommend most of these lenses (the “cheapies” in category 1 above) to anyone who’s at all interested in photographic image quality. The one exception is
probably the EF-S 18-55 kit lens included with the EOS 300/350/400 and Digital Rebel series cameras. This lens, while incredibly cheap, is actually not too bad if you
factor in the low cost. Especially if you stop down to f/8 or so when using it.
So what if you’re on a budget but really want the convenience of a zoom? Well, you could pick up a used zoom lens of an older generation, many of which have quite
decent optics for the price. For example, you could buy a used metal lens mount 28-70 3.5-4.5 II for nearly the same price as a new 28-80 all-plastic cheapie. If you
want a lens with silent-focussing USM you could consider the metal lens mount 28-80 3.5-5.6 USM (not one of the later plastic lens mount models with Roman
numerals), which has similar build quality to the 28-105 3.5-4.5 USM. Two other reasonable but discontinued lenses available inexpensively on the used market
include the 35-135 4.0-5.6 USM and the older 35-105 3.5-4.5. The main drawback is that these lenses aren’t really wide enough to be useful on cropped digital SLRs.
In short, you don’t have to put up with shopping mall quality just because you’re on a tight budget so long as you’re willing to consider used lenses.
Mid-priced zoom lens.
If you have a slightly larger budget, a mid-priced zoom (category 2) is worth considering. For example, two popular Canon zoom lenses are the 28-105 3.5-4.5 USM
and the 24-85 3.5-4.5 USM. Both are reasonably sturdy lenses with decent though not outstanding optical quality. They feature fast and silent ring USM autofocus
motors. They’re more expensive and heavier than cheap zooms, but most people find the tradeoff worth it.
Of the two lenses the former has a bit more reach and so is good for isolating objects or for doing simple portrait work. The latter has less reach but is considerably
wider (there’s a surprisingly big difference in coverage area between a 24mm lens and a 28mm lens) and so is popular for travel photos. The 24-85 is also a good
match for those digital cameras with less than full frame image sensors, such as the 300D/Digital Rebel/Kiss Digital or 10D.
If you’re interested in the 28-105 3.5-4.5 USM see the important note below about its similarly-named low-cost cousin.
What are some popular Canon EF and EF-S lenses?
Here are a number of popular Canon EF and EF-S lenses you might come across.
EF 16-35 2.8L USM and EF 17-35 2.8L USM.
Professional-quality new and old fast wide-angle zoom lenses, used by many photojournalists. Expensive.
EF 17-40 4L USM.
Affordable and optically slower version of the above, popular with advanced amateurs.
EF-S 18-55 3.5-5.6.
Pretty well every 300D/Digital Rebel, 350D/Rebel XT and 400D/Rebel XTi owner out there has one of these, since they’re bundled with most consumer Canon digital
SLRs sold. Image quality is OK considering the rock-bottom price.
EF-S 17-85mm 4-5.6 IS USM.
Very popular with users of Canon’s subframe D-SLRs, this lens combines decent image quality with a useful focal length range and has image stabilizing to boot.
EF 28mm 2.8.
Inexpensive lightweight wide-angle lens, suitable for landscapes and so on.
EF 50mm 1.8 and EF 50mm 1.8 II.
Super-cheap lightweight fast lenses, ideal for beginners and advanced amateurs. Take surprisingly sharp pictures for the price.
EF 50mm 1.4 USM.
Versatile standard lenses, useful in low light. These lenses contain micromotor USM mechanisms that unusually support full-time manual focussing.
EF 24-70 2.8L USM and EF 28-70 2.8L USM.
Large, heavy black L series lenses, noted for their high quality. Expensive and popular with wedding photographers.
EF 24-105 4L IS USM.
Very popular and quite expensive L-series image-stabilized walkaround lens.
EF 28-70 3.5-4.5 II.
Cheap older lenses with a reputation for decent optical quality despite the really low price. Rotating recessed end makes filter use awkward, however.
EF 28-80 3.5-5.6 II-V, 28-90 4-5.6.
Extremely cheap Canon lenses, supplied with many low-end camera bodies as kit lenses. Lousy optics.
EF 24-85 3.5-4.5 USM, 28-105 3.5-4.5 USM and EF 28-105 3.5-4.5 USM II.
Medium-sized, medium-priced and medium-speed lenses popular with many amateur photographers. The 24-85 is particularly popular with APS and subframe digital
EOS users owing to its wider short end. Do not confuse the 28-105 3.5-4.5 lenses with their cheaper and slower 4-5.6 cousins.
EF 28-135 3.5-5.6 IS USM.
Popular and versatile midrange lenses equipped with image stabilization for low-light shooting.
EF 85mm 1.8 USM.
Sharp and relatively inexpensive prime lenses, ideally suited for portraiture.
EF 100mm 2.8 Macro and EF 100mm 2.8 Macro USM.
True macro lenses capable of 1:1 closeup photography, yet equally useful as portrait lenses.
EF 70-200 2.8L USM and EF 70-200 2.8L IS USM.
Heavy white L series lenses, favoured by a lot of photojournalists. Expensive.
EF 70-200 4L USM.
Optically slower and less heavy siblings to the 2.8L. Considered a bargain for the price by many photographers, and popular with advanced amateurs.
EF 70-200 4L IS USM.
The image stabilized version of the 4L. Much more expensive, however.
EF 70-300mm 4-5.6 IS USM.
A popular lens for its compromise between size, convenience and image quality. Much sharper than its 75-300 predecessors, and image stabilization is a big plus. Not
to be confused with the DO (diffractive optics) lens, which is extremely expensive.
EF 75-300 4-5.6.
Commonly available cheapie-series telephoto lenses (see below). Ubiquitous owing to the low price, but optically poor.
EF 1200mm 5.6L USM.
Okay, so these gigantic and insanely expensive telephoto lenses aren’t popular as such, but always feature prominently in Canon’s lens advertising. Canon will gladly
custom-build one for you, given a prepaid order. I think they run for roughly the cost of a luxury automobile.
Frankly if you need this sort of focal length you’re better off with the 600mm 4L IS USM and a 2x teleconverter, though admittedly you’ll need an EOS 1V, 1D, 1Ds
or 3 to autofocus with it.
Should I buy a non-Canon (third party) lens?
Despite Canon’s vigorous advertising campaign against third-party lenses a lot of people happily use lenses made by Tamron, Tokina and Sigma (and lenses with
other brandnames but probably built by one of those three). And there’s one really good reason for this - the third party lenses are almost always much much cheaper
than equivalent offerings from Canon.
So. Should you buy a third party lens? It’s not a simple yes/no issue, so here are some points to consider.
• Price savings of third party products can be considerable, particularly if you’re looking to get a faster, higher-quality zoom lens.
• Remember that the cheapest lenses are optimized for price, not for optical quality. And the profit margins for cheap products tend to be very thin. The
price differential between Canon and third party isn’t huge when it comes to super-cheap lenses, so I don’t know if third party lenses are such a great idea in this
case.
• Third party makers produce lenses in a variety of market categories. Conventional wisdom is that if you’re considering third party at all you should
consider the higher end of their product line, not the lower end for the reason above.
• On the whole, Canon lenses seem to hold up their used value more than third party. If you intend to resell the lens anytime soon this can be a
consideration.
• Camera salespeople seem very eager to push third party lenses, so it’s likely that they receive bigger kickbacks from the manufacturers in return. Don’t
let yourself be swayed by an eager salesperson - he or she probably isn’t trying to convince you to buy something for your benefit.
• Buying Canon is pretty well a guarantee that your lens will work with any Canon EOS camera. However Tamron also have an excellent compatibility
record with EOS cameras. Always test with your camera first, but be aware that the lens may not necessarily work with future EOS cameras.
• Some older Sigma lenses do not work correctly with the latest EOS cameras. They fit the camera but don’t have compatible electronics, so the camera
tends to lock up when you try to shoot. If you have such a lens you’ll need to contact the manufacturer to see if they can provide a free repair to the problem. The
lenses don’t damage the camera - they just cause a temporary lockup that’s quickly cured by turning off the camera and turning it back on again.
• Build quality of older Sigma products is notoriously inconsistent. A quick search of the Web reveals countless complaints from unhappy Sigma lens owners.
Newer Sigma lenses seem to be a bit sturdier, judging by anecdotal evidence.
• Many of Tokina’s lenses have heavy metal lens barrels, which take a lot of abuse but are a drag when hiking.
• Canon offer many lenses with USM and full-time manual. Most third party lenses don’t have these features.
• There are some operational differences. For instance, some third party lenses have focus or zoom rings which rotate in the opposite direction from the
usual Canon direction.
• It’s difficult finding useful comparative data. You can look up the MTF scores on sites such as Photodo, which is a useful guideline, but the only way to
compare lenses properly is to test them yourself to see if they meet your needs. Asking, “Is the Tokina XYZ 2.8 lens better than the Canon XYZ 2.8 lens?” rarely
yields helpful answers, because most people don’t buy both lenses and try them out.
• Some specific third party lenses are better known than others. For example, Tamron’s 90mm macro lens has a reputation for excellent image quality at a
price considerably less than Canon’s 100mm macro. Sigma sell an 8mm fisheye which Canon do not make.
• But the biggest deciding factor is, as always, money. Only you can decide what’s your priority - low initial purchase price, mechanical reliability,
compatibility, user interface or optical quality.
Types of lenses.
Why doesn’t my camera have a motorized zoom lens with wide/tele buttons?
Because it’s not a point and shoot. Such motorized lenses are fine for simple tiny consumer-oriented cameras, but SLRs with interchangeable lenses are meant for a
different market.
All Canon EF zoom lenses but one are manual zooms. That is to say you adjust the focal length either by turning a ring (two touch) or sliding the lens in and out
(push-pull). And most people find that adjusting the zoom setting on such lenses is much faster and more precise than a slow and cumbersome motorized point and
shoot zoom lens.
Note that Canon did briefly sell a motorized zoom lens for EOS cameras a while back, presumably as a sort of experiment. That lens, the Canon EF 35-80 4-5.6 PZ
(Power Zoom), was an all-plastic cheapie with fairly low optical quality. The lens barrel had two pushbuttons that let you adjust the zoom position.
What’s the difference between all the Canon 28-105mm lenses?
Canon sell and have sold a number of different lenses which use the 28-105mm focal range.
28-105mm 3.5-4.5 USM, flower icon.
This is the first version of this popular lens, released in the early 1990s. It’s a midrange consumer zoom with decent optics and a fast and silent ring USM motor with
FTM. The mark I version with a flower icon on its lens barrel apparently had a 5-blade aperture diaphragm. Marked with a striped gold line since it’s a USM lens,
and has a metal lens mount. Discontinued.
28-105mm 3.5-4.5 USM, “MACRO” icon.
This is the second version of the lens, though it was never officially identified as such - it’s still considered to be a mark I. It’s identical to the first version but it has
the word MACRO printed on the lens barrel in lieu of the flower (closeup) icon. Internally, however, it has a 7-blade aperture diaphragm, which in theory offers
slightly better bokeh, or out-of-focus blurring. Marked with a striped gold line since it’s a USM lens, and has a metal lens mount. Discontinued.
28-105mm 3.5-4.5 USM II.
This is the official second version of the lens, as indicated by the II symbol. According to Canon the original 28-105 and the mark II versions have identical optics, but
the mark II version has slightly different external styling, including an allegedly slightly tougher design. According to Canon Malaysia an internal component used in
the zoom mechanism has been updated to metal from plastic. Marked with a striped gold line since it’s a USM lens, and has a metal lens mount. Discontinued.
28-105mm 4-5.6 USM.
This lens is a cheapie lens, released in 2002. It is a completely different and very much inferior lens from all the ones listed above. It’s almost entirely made of plastic
(including the lens mount) and has vastly worse optics than the faster lenses. It can easily be identified by the silver (chrome) ring around the end of the barrel.
Interestingly, while it uses a micromotor USM autofocus system it nonetheless supports full-time manual, according to Canon’s literature. It’s a lens intended for
consumers and does not fit the same position in the lineup as the 28-105 3.5-4.5 USM II.
In short, be very careful when shopping for a 28-105 lens. You don’t want to buy a lens thinking it’s the popular midrange lens only to end up with the bottom of the
line cheapie instead. Always double-check the listed aperture range before buying.
Should I buy the Canon 28-200 or the Tamron 28-200 or the Sigma 28-300 (or some other lens with a big focal range)?
A popular question back in the late 90s, when such lenses were heavily marketed as the ultimate in consumer convenience since they cover such a huge focal length
range. Sadly, the lenses tend to be fairly big and heavy, as consumer lenses go. And most importantly, the optical quality of these lenses leaves a lot to be desired.
It’s very difficult to build optically sharp zoom lenses, particularly those with a really wide zoom range like these ones. The lenses are pretty slow, with small
maximum apertures. They also tend to have a lot of distortion, which makes squares and rectangles in photos appear like they’re bulging in or out slightly - bad for
photos of buildings.
If you only take 4"x6" snapshots then these drawbacks are probably fine, but if you ever want to make enlargements beyond that you may find that your photos look
disappointingly soft - not very sharply focussed. Since they’re optically so slow you’ll probably also find that any telephoto photos you take will be badly blurred
unless you use a tripod or flash. Finally, using long telephoto lenses requires a certain degree of technique and experience since the focal lengths are so long. You
can’t easily handhold a slow 300mm lens, for example. Doing so, particularly without high-powered flash, is a surefire recipe for disappointingly blurry photos. And
Sigma has regrettably a long history of older lenses turning out to be incompatible with later EOS cameras.
As a beginner you’re probably best off getting one or two lenses of a more modest focal length range, no matter what nonsense the salesperson in your camera shop
may say about you never needing to buy another lens again. In short, consumer-level 28-200 or 28-300 lenses always suffer from tremendous optical compromises;
compromises which render them of limited value, especially at the long (200-300mm) end.
There are really only two lenses with a huge focal length range that are generally accepted as possessing decent optical quality - Canon’s 35-350 3.5-5.6L and
Canon’s 28-300 3.5-5.6L IS. However both are gigantic and expensive lenses not intended for beginners.
What affordable Canon long telephotos are there?
Canon make telephoto zooms which fall mostly into two basic categories - very cheap slow lenses with mediocre optical quality and very expensive fast lenses with
fabulous optical quality. There are few intermediate choices, though the 70-300 4.5-5.6 IS USM is one to consider. Canon have also never built any affordable long EF
telephoto prime lenses - all EF telephoto primes longer than 135mm are L series lenses.
There are a number of Canon zoom lenses in the 75mm to 300mm range, however. Here’s a bit of basic information about some of them.
75-300 4-5.6
75-300 4-5.6 USM
75-300 4-5.6 II
75-300 4-5.6 II USM
75-300 4-5.6 III
75-300 4-5.6 III USM
Canon sell and have sold quite a few different lenses with focal lengths from 75mm to 300mm. All apparently use the same optics - they just have different cosmetic
styling of the lens barrel (the mark III version, for example, has a silver ring on the end to impress novice camera buyers) and different autofocus motors. They’re
very inexpensive lenses as telephoto zooms go, but offer fairly mediocre optical quality. At the short (75mm) end they’re not too bad but at 200-300mm they tend to
get very soft (slightly blurry). You really need to stop them down to f/8 or f/11 or so for okay optical quality, which of course requires longer shutter speeds.
The 75-300 USM models all have micromotor USM autofocus mechanism which do not support full-time manual (FTM). All other versions of this lens use slow and
noisy micromotor or DC motor drives. These lenses, while in the “cheapie” category of Canon lenses, have metal lens mounts. They do not, however, have distance
scales. All versions of this lens have rotating ends when focussing, which makes using a polarizing filter rather inconvenient.
75-300 4-5.6 IS USM
One notable lens in the 75-300 series is the IS model, which offers image stabilization for improved shooting at lower shutter speeds. It was the first IS lens offered by
Canon, but the lens sadly has the same unremarkable optics as the other 75-300 lenses.
70-300 4.5-5.6 IS USM
Do not confuse this lens with the cheaper 75-300 crowd or the more expensive DO lens with almost the same name. This lens combines decent optics with image
stabilizing and is an excellent compromise for the advanced amateur. It’s not quite as sharp as the 100-300 5.6L, but IS makes it a lot more convenient since you end
up with a much higher percentage of keepers when used off-tripod.
70-300 4.5-5.6 DO IS USM
This lens is particularly unusual in that it’s the first zoom lens to use diffractive (DO) lens elements. This Canon technology allows for smaller and lighter lenses. The
70-300 DO is considerably shorter than its 75-300 siblings, and has image stabilization (IS) technology to boot. It isn’t cheap, however. Do not confuse it with its
non-DO sibling.
90-300 4-5.6 USM
I really don’t see the point of this lens. It appears to be pretty well the same as all the cheap 75-300 lenses, only its short end starts at 90mm. It’s USM but only
micromotor USM and thus has no FTM.
100-300 4.5-5.6 USM
This lens is, in terms of build quality and physical appearance, the telephoto zoom counterpart of the 28-105 3.5-4.5 USM and the 24-85 3.5-4.5 USM. It has
reasonably solid construction, a fast and silent ring USM autofocus drive which supports full-time manual (FTM), does not having a rotating end and has a distance
scale. Optically the 100-300 USM I had was very slightly sharper than the 75-300 at the long end, but many people report that there’s really no difference between
their samples of the lenses. Essentially the 100-300 USM gives you improved focussing speed and a more convenient user interface compared to the 75-300s, but not
improved optics. You also lose 25mm and half a stop off the short end, for what it’s worth.
70-210/3.5-4.5 USM
The predecessor to the 100-300 4.5-5.6 USM. Very similar in size and construction, only with a focal range that’s shorter at each end. Offers similar optical quality.
100-300 5.6L
An older and now discontinued lens, the 100-300 5.6L is an interesting lens in that, while it’s technically an L series lens with fluorite and UD lens elements, it doesn’t
have the tough build quality of a typical L series lens sold today. It uses a slow and noisy AFD autofocus motor and has an awkward (low-profile) and fiddly (hard to
slide) MF/AF switch. The manual focus ring is also rather gritty to turn. However, it does offer considerably improved optical quality over the 75-300 series and the
100-300 USM. It's also sharper than the 70-300 IS USM. So if you can deal with the slow optical speed (maximum aperture of only 5.6) and the horribly sluggish
autofocus motor it’s well worth looking into if you’re on a tight budget.
50-200/3.5-4.5 L
Similar to the 100-300 5.6L, in that it’s a first generation EF-mount L series lens. It has the optics of a modern L series lens - but not the build quality - and has a
push-pull zoom design. The 50-200 isn’t a bad lens, but for some reason holds its used market value rather well. Personally I think the 70-200 4L USM is a better
deal. It’s typically not much more money but gives you better build quality and silent focussing USM.
70-200 4L USM
This lens, the smaller and cheaper sibling of the impressive 70-200 2.8L USM professional lens, is considered a bargain by many EOS users. It costs three times as
much as the cheapie lenses but it’s sturdy, focusses quickly with a ring USM system with FTM and, most importantly, it has great optical quality. It’s bigger and
heavier than the consumer lenses, but if you want something good but can’t afford the 2.8L, consider this lens. It doesn’t use a huge 77mm filter like the 2.8L - it uses
a 67mm filter like the 24-85 3.5-4.5 USM. This is a little unfortunate, has hardly any other Canon lenses have 67mm filters.
70-200 4L IS USM
The image stabilized sibling to the 4L. Visually almost identical, down to the 67mm filter, but much much more expensive than its non-L counterpart. According to
some reviewers, one of the sharpest Canon lenses in its whole zoom lens range.
80-200 4.5-5.6
80-200 4.5-5.6 USM
80-200 4.5-5.6 II
Plastic cheapies, basically analogous to the 28-80 plastic cheapies. They are very lightweight and portable, though. If you want something really inexpensive and
never enlarge your photos past postcard size then they’re fine.
100-300 5.6
With pretty well identical build quality to the 100-300 5.6L, this older lens has all the disadvantages of the 5.6L without the sharp optical quality of the L lens.
I want to take photos of wild birds. What lens do I need?
You probably won’t want to hear this answer, but nature photography of small and fast-moving wild animals is a difficult field and basically requires really expensive
lenses. 500mm and 600mm lenses are commonly used by bird photographers - your typical 100-300mm zoom lens is just not long enough for great photos. And lenses
longer than 300mm are both incredibly expensive and really heavy.
So the harsh reality is while you may be able to get nice snapshots of fairly tame birds with a 100-300mm lens you won’t be able to get those amazing wildlife book or
calendar shots - small birds filling the entire frame - with one. You can always use your lens at 300mm and then crop off the edges of the picture, but then picture
quality will suffer.
If you really want to do this type of photography on a tight budget you might want to consider buying used manual focus gear. You can find really quite decent used
high-end manual focus telephotos quite inexpensively compared to their autofocus counterparts.
I want to do sports photography. What lens do I need?
Unfortunately, this answer is going to be somewhat like the previous one. The challenges of sports and other action photography are twofold. First, by its very nature,
sports photography tends to involve rapid motion - fast-moving players or cars or whatever. Second, usually there’s some distance between the action and the camera.
Solving the first problem requires lenses which can let in plenty of light, the use of flash or faster film or high ISO settings on a digital camera. Each of these solutions
has drawbacks, however. Fast lenses are large, heavy and expensive. Fast film or high ISO settings result in higher grain or noise and thus lower picture quality. And
flash may be inadequate to illuminate the subject effectively, particularly if the subject is some distance away.
Solving the second problem basically requires the use of long telephoto lenses. However, most affordable autofocus telephoto lenses are very slow - they don’t let in
much light. So this amplifies the first problem.
Now obviously there are some cases where these two issues aren’t a massive problem. For example, perhaps you’re shooting a basketball game and you’re in the
front row. Basketball courts are of a modest size and so you could probably do okay with flash (assuming you’re allowed to use flash - some places won’t let you as it
can temporarily blind or distract the players) and you won’t need an incredibly long lens accordingly. Such a situation is a little less challenging than shooting hockey
on a big, poorly lit, rink.
Nonetheless, pro photographers rely on fast lenses, and this is the primary stumbling block for amateur photographers on a budget. Fast telephoto lenses, especially
fast telephoto zooms, are really expensive. And there’s not much you can do to work around that fact without a lot of compromises. To cover these points further:
Fast lens. Get the fastest (largest aperture) lens you can afford. A 70-200 2.8 lens is great for basketball, for example. A 75-300 4-5.6 is probably not, since even
shooting wide open means you’ll have slow shutter speeds, which will result in unwanted motion blur.
Telephoto lens. You’ll need a long telephoto zoom unless you’re planning on shooting very close to your subjects. For example, you won’t need a long lens to shoot
skateboarders in an urban setting, but you will if you’re covering a football game.
Cropping. You can always make up for a long lens to a certain extent by cropping the picture - trimming off the edges. The problem with this is that enlarging the
picture also enlarges the grain in the case of film and lowers the apparent resolution in the case of digital.
Image stabilization. Useful for reducing blurring caused by camera motion, but of no value whatsoever in freezing subject motion.
Flash. Useful both for illuminating the subject and freezing subject motion. Not every venue permits flash usage, however.
Film/ISO speed. Fast film or high ISO settings are needed to keep shutter speeds to a minimum. Once again this involves tradeoffs with picture quality.
Camera with fast focus. A fast pro camera (such as the EOS 1 series) can lock focus surely and accurately and has minimum lag time when the shutter release is
pressed. A consumer camera is not going to be as surefooted and decisive, and will make it harder to nail the perfect shot.
Fast lens motor. A Canon ring USM lens can autofocus rapidly, whereas a Canon AFD (arc form drive) lens cannot. A lens with a rapid motor frequently makes the
difference between achieving a shot and getting nothing.
To summarize - if you plan on putting a 75-300 4-5.6 consumer lens onto your camera, don’t expect photos like those which grace sports magazines. This isn’t to say
that you can’t get satisfactory photographs with such equipment, just that it’s challenging to do so. It takes a lot of skill, experience and luck to come up with
consistently good results. And you should be operating on the expectation that you will face problems with blurring of the subject and general low sharpness and low
contrast if you use an affordable consumer telephoto zoom lens.
What about mirror lenses? I can get a really cheap telephoto that way!
Some third-party lens makers sell mirror or, as they’re more accurately known, catadioptric lenses. Such lenses use a pair of mirrors to fold the light path in half, in
addition to containing regular glass elements. The advantages are that mirror lenses can be made fairly cheaply and will also be shorter and lighter than all-glass
(refracting) lenses of the same focal length. And mirror lenses with focal lengths of 500mm to 1000mm are not uncommon. Russian makers produce a lot of these
lenses.
Unfortunately mirror lenses have a number of drawbacks. First of all, they’re manual-focus only. Second, they are optically really slow lenses - usually around f/8 or
so. Third, they don’t have aperture diaphragms, so the only way to adjust the exposure is to adjust the shutter speed, the film speed/digital ISO or to put a neutral
density (darkening) filter on the lens. Fourth, the smaller of the two internal mirrors blocks the light path somewhat, resulting in rings or doughnuts appearing around
bright highlights in out of focus areas. This effect, a form of bokeh, can be visually very distracting. And fifth, they tend optically not to be of the highest quality -
you’re not going to get National Geographic-quality bird photos using them.
So, while such lenses are attractive if you’re on a budget, they do have many limitations associated with them. You’re probably better off buying a used manual-focus
refracting (non-mirror) lens and adapting it to your camera, or buying a manual-focus body. As noted above, photography can be a really expensive endeavour.
What is a macro lens? My lens has MACRO written on it.
Macro photography is the somewhat confusing name for closeup photography. Just as the human eye can only focus up to a certain distance (a distance which moves
alarmingly further away with age), not all lenses can focus as closely as others. Most lenses are designed to focus up to a metre or two with long telephoto lenses
having much longer minimum focussing distances than that.
Now this obviously isn’t going to help you if you want to take a super closeup of a small flower - you need a much shorter minimum focussing distance. Basically you
want to be able to fill the frame with your small subject. And another concept comes in - the magnification factor. Traditionally, true macro photography refers to 1:1
photography and smaller. In other words, a lens with 1:1 magnification is able to image an area as small as the exact size of the image format in question. In the case
of 35mm film this means an area of 24x36mm in size. Sometimes magnification is written as a decimal factor, such as 0.25x or 1.0x.
Unfortunately, lens manufacturers tend to throw around the word “macro” with cheerful abandon as a marketing gimmick. The fact a lens has MACRO printed on it
basically means nothing, and you have to look closely at the lens specs. If a lens can do 1:1 or 1:2 photography then it’s a real macro lens, optimized for closeup
photography. It may also be designed with a flat field so it can be used to take photographs of flat objects like stamps without focus problems. Lenses that can only
reach 1:4 or whatever can’t take really close-up pictures.
True macro lenses are generally of much higher optical quality than ordinary lenses and usually cost more. They are also usually optimized to take photographs of
small flat objects with even focus across the surface - flat field. They’re still a good buy if you don’t do a lot of macro photography, however. You can always use them
for regular photography as well - they just have the bonus that they can focus much closer than ordinary lenses can.
What is a portrait lens?
Obviously any lens can be used to take a portrait of someone. However, the results can be very different depending on its focal length.
The distance required between you and your subject, when you take a head and shoulders portrait, depends on the focal length of the lens. If you have a wide angle
lens then you need to stand very close to them in order to have their head and shoulders fill the frame. But if you have a telephoto lens then you need to stand a fair
distance away from them for the same effect.
This distance results in a change in perspective. Try this experiment with someone in real life without using a camera. If you stand really close to the person and look
at their face you’ll notice that this position tends to emphasize their nose and make their forehead look like it’s sort of sloping away. But if you’re further away from
them then their face tends to look flatter. And generally speaking people find that a slightly flatter perspective on a face is usually a bit more flattering in general.
Portraits taken with wide-angle lenses can, in fact, have a rather comical or grotesque effect.
So generally photographers like to use lenses of about 85mm to 135mm in length when taking head and shoulders portraits, depending on the look they’re trying to
achieve. Some fashion photographers even use 200mm and 300mm telephotos for a particularly flat effect. You can take photos of people with 50mm and shorter
lenses, but these lenses tend to distort the face somewhat. Such shorter focal lengths are, however, perfectly fine for waist-up or full body shots.
Canon make a number of of popular lenses used for portrait photography. Two of the more affordable ones include the compact and sharp 85mm 1.8 and the 135mm
2.8 SF which has a “soft focus” feature which allows you to introduce image-softening at will.
Finally, note that the lens focal lengths I list here are for 35mm film or full-frame EOS SLR. If you’re using a camera with a smaller image area - digital or APS - then
the ideal focal lengths for portraits are going to be shorter. For example, a 50mm lens is generally considered a bit short for most portraiture with 35mm film, but
when mounted on an EOS 10D digital camera it takes photos much like those taken with an 80mm lens on a 35mm film camera.
What is a fisheye lens?
Most lenses are “rectilinear,” which means they’re designed to project an image onto a flat surface (the film or the image sensor) and render straight parallel lines as
straight parallel lines. This is actually a complicated optical trick, since a simple lens really wants to project an image onto a spherical surface (such as the interior of
the human eyeball). It also becomes increasingly complicated to do as the field of view of the lens becomes larger, as with wide-angle lenses - one reason why really
wide angle lenses are so expensive.
This type of projection onto a flat field is something that different lenses do to varying degrees of success. High quality lenses, particularly those intended for use for
macro or architectural photography, do a pretty good job. But cheaper lenses will compromise on this slightly and will either barrel or pincushion somewhat. That is to
say, a photograph of a square object may appear to be either bulging outwards or squashed inwards, because parallel lines are being portrayed as curved. In fact,
nearly all cheap lenses tend to have barrel distortion - it’s just that people usually don’t realize it because they rarely take photos of square or rectangular objects.
A fisheye lens is a wide angle lens where no effort has been taken to render parallel lines as parallel. Instead, only lines which pass through the centre of the frame
are straight. All other lines appear as curves, becoming increasingly curved as you near the edge of the frame. This line curvature has the effect of making near
objects seem closer and more distant objects seem further off, as they fall away. If you’ve ever looked through the glass peephole viewers in a door then you know
the effect.
Sometimes people call rectilinear lenses “corrected” and fisheye lenses “distorting,” but I don’t think that’s very useful or accurate. Rectilinear lenses aren’t
necessarily correct - a wide-angle lens has extreme distortion and stretching towards the edges to make the lines straight. That being said, the fisheye effect is very
pronounced and extreme, and does render scenes in a characteristic fashion. Portrait photographs of people taken with fisheyes, for example, have cartoon-like
bulging noses and so on.
Fisheye lenses are useful for three basic things. First, it’s a lot easier to make a super wide angle fisheye than it is a super wide angle rectilinear lens, so a fisheye
lens is going to be cheaper than its rectilinear equivalent. Second, and this is how fisheyes came about, it’s possible to build a fisheye lens which covers a full 180°
field of view, which is very handy for scientific photography, particularly of the sky. And third, bulgy wide angle effects are fun for taking crazy trippy photographs.
There are two basic types of fisheye lenses. Circular or 180° fisheyes cover a full (or nearly full in most cases) 180 degree field of view across the narrower side of
the image rectangle. These lenses make photos that look like bulging circular balls on a black background. The other type are sometimes called full frame or semi
fisheyes and basically offer a cropped field of vision so you don’t get the black areas at the corner of the picture. As a result they only cover 180 degrees of view on
the diagonal.
On 35mm cameras, full frame fisheyes usually have a focal length of 8mm, and semi-fisheyes have a focal length of 15mm or 16mm. In near-circular lenses, Japanese
maker Sigma sell an 8mm autofocus fisheye for use with EOS cameras, and Belarus maker Peleng sell an 8mm manual-focus fisheye that can be adapted to EOS
cameras. In full frame fisheyes, Canon sell a 15mm autofocus fisheye for EOS, and Russian maker Zenitar sell a 16mm manual-focus fisheye lens which can be
adapted. There are also popular screw-on adapters that convert ordinary lenses into fake fisheye lenses. Such adapters are virtually all of extremely low quality, but
are definitely fun to play with.
A lot of photographers turn up their noses and dismiss fisheyes altogether as gimmicky remnants of the 1970s. Personally I think fisheye distortion can yield
interesting effects if used occasionally, but it’s obviously not something you’re likely to use every day. In nature or underwater photography, where there are few
straight lines, fisheyes can be a useful tool as well.
Lens features.
What is the difference between two-touch zoom and push-pull zoom?
There are two basic ways to adjust the focal length of a zoom lens. Some zoom lenses have a zoom ring as well as a focus ring and so are called two-touch. Rotating
the zoom ring adjusts the focal length. Other lenses slide in and out like a trombone or telescope; the so-called push-pull design.
The push-pull design is more vulnerable to zoom creep than two-touch. This is the problem of the zoom accidentally adjusting focal length (sliding) when tilted up or
down because the friction of the push-pull system isn’t enough to counteract the weight of the lens. Push-pulls also tend to suck in a lot of air and therefore dust into
the lens when adjusted. However, push-pull lenses can be operated more rapidly, if usually a bit less accurately, than two-touch zooms.
Why are some Canon lenses painted white or silver?
Nearly all large telephoto L series lenses have barrels constructed from solid metal and painted off-white, rather than black plastic or black-painted metal. Canon say
they do this since white surfaces absorb less heat than black when used out in the sun, and fluorite crystal lens elements are sensitive to heat - they can expand and
contract, altering their optical properties. Of course, the fact that a white-painted Canon lens stands out in the crowd is probably part of the reason as well. Look at
any major sports event and you’ll see rows of hefty white lenses. Though to confuse matters Nikon have also begun to sell some lenses in optional white paint.
A few lenses intended to be sold as kit lenses with silver-painted camera bodies have also been available with silver-painted plastic barrels. These include the 35-135
4-5.6 USM (to match the silver-painted commemorative edition of the EOS 10/10s which was released to mark the sale of 60 million Canon cameras), the 24-85
3.5-4.5 USM (to match the APS IX camera) and the 28-90 4-5.6 USM II (to match the Rebel Ti/EOS 300V/Kiss 5). The silver paint on these midrange and low end
lenses is purely for cosmetic reasons.
What is a tripod mount on a lens for?
Normally you put a camera onto a tripod by attaching the camera body right to the tripod head itself. But if you have a really heavy lens this is a bad idea. Large
lenses can often weigh far more than the heaviest SLR cameras. So the right way to do it is to attach the lens to the tripod head via a tripod mount. The camera then
sort of hangs off the back of the lens unsupported, but this isn’t a problem - lens mounts are designed to handle that kind of weight easily.
Lens tripod mounts or collars are mounting rings with built-in clamps. These rings make it easy to rotate the camera from portrait (vertical) to landscape (horizontal)
position. If the maker of your lens sell a tripod mount for the lens then it’s probably wise to get one.
What is a distance or depth of field scale?
Most Canon EF midrange and better lenses have distance scales - clear rectangular plastic windows set into the lens barrel. A series of numbers can be seen through
this window indicating the distance, in both metres and feet, from the lens to the point in focus. Inexpensive consumer lenses generally do not have distance scales.
Canon EF prime lenses also have simple depth of field scales marked on the barrel below the window. These marks indicate the acceptable depth of field distances
from the current focus distance, usually for a small number of apertures - f/11 and f/22, say, or f/5.6, f/11 and f/16. Canon EF zoom lenses, however, do not have any
depth of field scales because of the complexity of indicating depth of field over varying focal lengths.
You’ll notice that there is usually a red dot on the distance scale window as well. This is used for determining the focus distance when using infrared film with an
infrared filter. Since infrared energy focusses at a different point from visible light this dot is a useful aid. However, if you’re using infrared film with an ordinary red
filter or no filter at all then you may not need to adjust focus using this dot, since much of your image is going to be visible light anyway. For more information please
consult my Infrared Myths document.
What is the issue with a rotating end of a lens?
Some lenses have an outer end which rotates when you adjust either the focus or the zoom setting or both. Others do not.
This matters a lot if you’re using a polarizing filter or a graduated neutral density (ND) filter, since the properties of the polarizer vary depending on its angle of
rotation and the graduation line runs across the filter in a straight line. It can be very annoying to set a filter to achieve the effect you want, touch up the focus, and
find that the polarizing or graduated ND effect has changed because the end of the lens has rotated.
Why does it matter how many blades the aperture diaphragm has?
The adjustable aperture diaphragm in most camera lenses consists of a number of flat wedge-shaped metal blades. As you adjust the lens aperture settings these
blades rotate in or out, and the aperture opening changes size in an iris-like fashion.
The shape of the hole made by this adjustable diaphragm depends on the number of blades and the shape of the blades. For example, if you have a 5 blade aperture
diaphragm then the aperture will be a pentagon in shape. An 8 blade aperture diaphragm will of course yield an octagon.
There are two areas in which this aperture shape affects the final image. First, the shape of lens flare on a photograph is typically governed by the shape of the
aperture. You may have seen photographs with pentagonal or hexagonal lens flare, for example, or star-shaped highlight areas in a photograph taken with a small
aperture setting. Second, it’s generally held that the closer the aperture is to a circle the smoother out of focus areas (bokeh) tends to be, though it isn’t the only
factor contributing to bokeh. Many lenses have at least 6 or 8 aperture blades, frequently with curved edges, to approximate a circular aperture opening for this
reason. Canon have in fact started billing some of their recent lenses as having “circular” apertures, indicating near-circular openings.
Which lenses are weather-resistant?
Most of Canon’s new professional (L series) lenses introduced since mid 1999 are equipped with gaskets and rings to keep out dust and moisture. They’re not
waterproof, by any means, so don’t go diving with them. But they’re much more resistant to inclement weather than Canon’s other products.
Of course, a weather-sealed lens isn’t much good unless you have a weather-sealed camera to match it. And at present only the top of the line EOS 1V, 1D, 1Ds 1D
mark II, 1Ds mark II and 1D mark IIN cameras (but not the 1, 1N or 3, which have lesser sealing systems) have the same level of weather sealing - gaskets and
rings around every opening, button and switch, in fact. You can use the sealed lenses with non-sealed cameras, of course, but the gasket around the lens mount will
still let in water unless mated to the gasket around a sealed camera. (this rubber ring around the lens mount is, incidentally, an easy way to tell if a lens is weather
sealed or not)
At time of writing the weather-resistant Canon lenses are:
16-35mm 2.8L USM
16-35mm 2.8L II USM
17-40mm 4L USM
24-70mm 2.8L USM
24-105mm 4L IS USM
70-200mm 2.8L IS USM
70-200mm 4L IS USM
28-300mm 3.5-5.6L IS USM
50mm 1.2L USM
85mm 1.2L II USM
300mm 2.8L IS USM
400mm 2.8L IS USM
400mm 4 DO IS USM
500mm 4L IS USM
600mm 4L IS USM
The mark II versions of Canon’s teleconverters, the Extender EF 1.4x II and Extender EF 2x II, also have weatherproofing. None of Canon’s more affordable lenses
or cameras have weather sealing. Note also that weather-resistant zoom lenses do not have sealed glass ends - you need to put a filter on these lenses to seal out the
far (non camera) end.
What is the close or minimum focus distance?
Just like a human eye, camera lenses have a near point at which they cannot focus anymore. This focus distance depends on the lens construction, but typically wide
angle lenses have nearer close focus distances than telephotos. Many macro lenses, of course, are optimized for near close focus distances.
If you’re a human you can adjust this close focus distance by moving the object you’re trying to focus on further away. Similarly you can add extension tubes to your
lens to move the lens further from the camera and thus bring the close focus distance closer. You will lose the ability to focus on infinity with such a tube, though.
Hey! I can turn the focus ring of my lens past the infinity mark! Why?
Your lens can go to infinity - and beyond! Yes, many lenses can be adjusted past the infinity marking on the lens barrel.
It’s not a problem. Such lenses are intentionally designed this way to allow the lens to compensate for the changes in optical characteristics that occur when the lens is
subjected to ambient temperature changes. (the focus of lenses can be affected by thermal expansion)
What does a lens hood do?
Aside from making the lens look longer and bigger and thus more impressive to non-photographers, lens hoods (sometimes called shades) serve two basic functions.
First, they help reduce the amount of stray light hitting the surface of the lens. This is a good thing, since non-image-forming light coming into the lens at an angle
results in lens flare. Lens flare can result in lower-contrast images or, in extreme cases like light from the sun, can result in big glowing blobs in the final photo.
Second, lens hoods serve as physical protection for the lens - the plastic or metal tube can absorb blows that might otherwise hit the glass itself.
Lens hoods come in a number of basic forms. The two types sold by Canon today are tube-shaped hoods and petal-shaped (notched) hoods, made of hard black
plastic. The petal-shaped type are sometimes called “perfect” lens hoods and shield the lens more effectively than simple tubes of the same weight. This is because
the notches are cut out to match the rectangular shape of the imaging area (think about it).
Some hoods clip onto the lens, some twist on bayonet-style and some screw onto the end. Some are lined with black light-absorbing flocking and some are not. You
can also buy flexible adjustable rubber hoods from third party makers, but Canon do not sell any such hoods themselves.
Unfortunately, lens hoods are hugely overpriced. Camera makers somehow feel justified in charging massive sums for simple moulded plastic tubes. Ah well.
How are lens hoods named?
Canon lens hoods are identified by a confusing and cryptical alphanumeric code. There is a system to the hood naming, though it’s only somewhat informative. Still, if
you understand how the hood naming works you can usually figure out which hoods can be interchanged with other lenses.
• The first letter in a hood name is E, indicating that the hood fits a Canon EF mount lens.
• The second letter is either W, S or T. W stands for Wide, S for Standard (probably) and T for Telephoto.
The letter refers to the type of lens to which the hood fits. W is for any lens wider than 50mm, S is for a 50mm lens (with a couple of odd exceptions) and T is for any
lens longer than 50mm.
• The two letters are then followed by a number which indicates the size of the hood mounting ring in millimetres. Some hoods fasten to the very end of the
lens barrel by means of a bayonet (rotating and locking) mount and others clip further down the barrel to a small ring by means of small spring-loaded plastic clips in
the hood. Generally newer lenses use the former style and older lenses the latter.
• The hood size is sometimes followed by a letter from A through D. This letter indicates the hood style, and unfortunately there’s no real way of knowing
what style fits what lens without looking it up, because the hood style appears to be chronological depending on when the lens was released and whether there
happened to be any lens hoods already in the lineup with otherwise identical specifications but with a different shape. There is no way to tell if the hood is a standard
tube or a petal shape (“perfect”) lens hood just by looking at this letter.
For example, the original EW-78 fits the 35-350 3.5-5.6L USM, the EW-78B fits the EF 28-135 3.5-5.6 IS USM, the EW-78C fits the EF 35 1.4L USM and the
EW-78D fits the EF 28-200 3.5-5.6.
• Finally, the hood name sometimes ends in a Roman numeral - typically either II or III. This indicates the hood version.
Generally speaking, mark II and III hoods are flocked on the interior with black anti-reflective material, like velvet. Hoods with no Roman numeral designation are
typically painted flat black, but since this depends in part on when the hood was released this is not a guarantee. Some mark II hoods also have slightly more
clearance around the end of the lens so that polarizing filters fit better if their predecessors didn’t.
Some hood naming examples:
ET-65 III
E indicates that the hood fits an EF mount lens.
T indicates that the hood fits a telephoto lens.
65 indicates that the hood mount is 65mm in diameter.
III indicates this is the third hood of the ET-65 series, and means in this case that the hood is flocked to reduce reflections.
This particular lens hood fits a number of Canon EF telephoto lenses - the 85 1.8 USM, the 100 2.0 USM, the 135 2.8 SF, the 70-210/3.5-4.5, the 75-300 4-5.6 and the
100-300 4.5-5.6 USM.
EW-78B
E indicates that the hood fits an EF mount lens.
W indicates that the hood is for a wide angle lens.
78 indicates that the hood mount is 78mm in diameter.
B indicates that it’s a hood of type B.
This particular hood fits the 28-135 3.5-5.6 IS USM.
ET-160
E indicates that the hood fits an EF mount lens.
T indicates that the hood fits a telephoto lens.
160 indicates that the hood mount is 160mm in diameter.
This gigantic hood fits the 600mm 4L USM IS.
Knowing this system you can figure a few things out. For example, the EW-65, ES-65 and ET-65 can all clip onto the same lenses - the only difference is the length.
The EW-65 is the shallowest lens and the ET-65 the deepest, so putting an ET-65 onto a 28mm 2.8 lens is a bad idea as you’ll get vignetting unless you have a
cropped image sensor on a digital camera. But you can put an EW-65 onto a 100-300 4.5-5.6 USM if you like. It won’t shield your lens as effectively as the longer
hood, but it’s better than nothing. Or if you can’t find the discontinued ES-65 you can always use the EW-65 instead.
General lens questions.
Is it okay to change lenses when there’s film in the camera?
Yes. A key advantage of a camera with interchangeable lenses is the ability for you to change lenses whenever you want. The camera body contains a shutter which
prevents light from hitting the surface of the film regardless of whether or not the lens is attached.
Of course, you should try not to change lenses when you’re outside in the pouring rain or in the middle of a sandstorm or whatever. And don’t poke your fingers into
the shutter itself as you’ll damage it.
Are there compatibility problems with any EF lenses made by Canon?
Basically, no. Any Canon EF-mount lens will work with any Canon EOS camera.
Now, there are minor compatibility issues with IS lenses on certain old EOS cameras - the lenses work, but IS control is a bit weird or the image may shake in the
viewfinder. Luckily this latter does not affect image quality of the photos at all. And autofocus-only EF lenses (a handful were made) are not much use on the oddball
EF-M camera, which was an EOS camera which lacked autofocus circuitry and which can only be used with manual-focus-capable lenses. But these are minor issues
on the whole.
Note that this compatibility issue is only slightly complicated by the introduction of EF-S lenses, in that an EF-S lens is not an EF lens. EF-S lenses, marked with small
white squares rather than raised red dots, can only fit EF-S bodies.
Are there compatibility problems with any EF lenses made by third party manufacturers?
Sometimes. Unfortunately certain third-party lenses not built by Canon, notably many older Sigma lenses, will not work correctly on some newer EOS camera bodies
like the Elan 7/EOS 30/33 and the digital EOS 10D. The most common symptom is the mirror flipping up and then the camera freezing when you try to take a photo.
You then have to switch the camera off to unlock it. The only solution to this problem is to see if Sigma will upgrade the lens for you. If they still have inventory of the
control chip they apparently will happily do so for free.
The only third-party maker of EF-compatible lenses with no major compatibility problems so far is Tamron. Some people have suggested that this is because Tamron
have licensed official lens protocol data from Canon, but Canon USA’s Chuck Westfall has stated repeatedly in public fora that Canon have never licensed their lens
mount protocol to any other manufacturer. So Tamron have either been very lucky or very clever in their reverse-engineering of the Canon lens system. They seem
to be a reasonably safe bet right now for compatibility, given their track record, but it’s impossible to predict future developments in this regard.
The following Sigma lenses require upgrading for compatibility with newer EOS cameras, according to Sigma:
24-70mm 3.5-5.6 aspherical UC
28-80mm 3.5-5.6 mini zoom macro aspherical
28-80mm 3.5-5.6 mini zoom macro aspherical HF
28-80mm 3.5-5.6 mini zoom macro II aspherical
28-105mm 2.8-4 aspherical
28-105mm 3.8-5.6 UC-III aspherical IF
28-135mm 3.8-5.6 aspherical IF macro
28-200mm 3.5-5.6 DL aspherical IF hyperzoom macro
28-300mm 3.5-6.3 DL aspherical IF hyperzoom
70-210mm 4-5.6 UC-II
70-300mm 4-5.6 APO macro super
70-300mm 4-5.6 DL macro super
100-300mm 4.5-6.7 DL
135-400mm 4.5-5.6 APO aspherical RF
170-500mm 5-6.3 APO aspherical RF
8mm 4 EX circular fisheye
15mm 2.8 EX diagonal fisheye
24mm 2.8
28mm 1.8 II aspherical
50mm 2.8 EX macro
105mm 2.8 EX macro
300mm 4 APO tele macro
400mm 5.6 APO tele macro
500mm 4.5 APO
500mm 7.2 APO
800mm 5.6 APO
28-70mm 2.8-4 UC
28-105mm 4-5.6 UC
28-105mm 4-5.6 UC-II
70-210mm 3.5-4.5 APO macro
28-200mm 3.8-5.6 aspherical UC
Can you use old Canon manual-focus lenses with EOS cameras?
Not really. In the years before introducing EOS autofocus cameras, Canon sold many manual-focus lenses for their SLR cameras. The majority of these lenses are of
the FD type. Sadly, FD lenses cannot be used with EOS cameras. The lens mounts are of incompatible sizes and types. This is in contrast to Nikon - most Nikon
manual-focus F-series lenses can be used with most Nikon autofocus cameras.
Now it is possible to use adapter rings to attach FD lenses to EOS cameras. Unfortunately it’s usually not worth the nuisance, in my opinion. There are just too many
drawbacks. I have a separate article on using manual-focus lenses with Canon EOS cameras, if you’d like to learn more.
Can you use non-Canon lenses with EOS cameras?
That depends. Many third party lensmakers - Tamron, Sigma and Tokina being the big three - manufacture lenses specifically designed to fit Canon EOS cameras.
These lenses will, of course, work fine with EOS cameras. The main caveat is the compatibility with the electronics detailed above.
However, if you have a third-party lens which does not physically fit onto your EOS camera then you can obviously assume that the lens will not work with EOS
cameras. Sometimes third party lenses can be adapted to fit EOS cameras by way of metal adapter rings, but it’s often not worth the bother. Autofocus will not work,
and apertures will have to be set manually on the lens. So adapting lenses this way is only worth it if you have a particularly unusual lens or are operating on a
particularly tight budget. For more information have a look at my using manual-focus lenses with Canon EOS cameras article.
I have a consumer Canon camera. Can I put a professional L-series lens on it?
Of course. As noted above, any Canon EOS camera works with any Canon EF (or compatible) lens.
The major issue you really have to be concerned about is weight, since a really heavy lens can strain the lens mount. The answer is to support the heavy lens by the
lens itself - just let the camera hang off the back of the lens. The weight of the camera is not going to strain the lens mount. This applies to all low to midrange EOS
cameras, since even those cameras with metal lens mounts have steel mounts attached to plastic body frames. All larger lenses either come with or have optional
tripod mounting brackets (see below), so you can attach the lens to a tripod rather than the camera body.
Now of course an inexpensive low-end camera won’t have the manual exposure control, focussing speed (AF speed is determined by both the lens motor and the
speed of the camera’s computer and AF sensors) and film-winding motordrive speed to make full use of a top of the line lens the way a professional would like it. And
a small camera will feel unbalanced and cumbersome on a large lens. But it’s better to have a great lens on a so-so body than the other way around. Renting
professional lenses is a great way to learn and practice when you’re on a budget.
This brings up the other issue which might arise - snide looks from camera ignoramuses who think that your little Rebel Ti camera isn’t fancy enough for the 70-200
2.8L you’ve got fastened to it. Ignore them. They’re probably the sort of wealthy dummy who rushes out and buys an EOS 1V and then sticks a cheap consumer lens
on the end.
What’s the big deal about f/8?
Most lenses provide sharpest results when used in the middle part of their aperture range. Lenses usually have performance problems when used wide-open.
Stopping down helps a great deal, but once the aperture becomes too small then an optical phenomenon known as diffraction comes into play and the quality
deteriorates once again. So most lenses work best at around f/8 or f/11 or so.
Naturally this sharpest point (some people call it the “sweet spot”) varies from lens to lens, so some testing would be required to find what’s actually best with a given
lens. And the effect is generally more pronounced with less expensive lenses. Really high-quality lenses are often almost as sharp wide open as they are stopped
down.
What is a focal length multiplier (or cropping factor) for digital and APS cameras?
35mm film has an image area of 24mm by 36mm. These are the exact dimensions of the area on the film to which an image is recorded.
Medium to low-end digital cameras sold today have sensor chips smaller than 24x36mm in size, since producing a 24x36mm image chip is still quite expensive to do.
Similarly, APS film records to an area of film 16.7x30.2mm in size.
The upshot of this is that if you use such a digital or APS camera you’ll be taking photos which do not record the same image size as 35mm film. So it’s like taking a
photo using 35mm film and then cropping out (snipping off) the edges. Imagine drawing a smaller rectangle within a given 35mm photo and then cutting it out - you’ve
got a digital or APS photo.
This cropping factor is often confusingly referred to as a focal length multiplier. This is because the cropping makes, say, a 50mm lens on an APS camera behave
rather like a 70mm lens on a 35mm camera. Not because the focal length has actually changed - it hasn’t - but because of this cropping of the image. The cropping
factor is sometimes specified as a numeric value - 1.3x or 1.6x, say.
If you want to use your lens to take photos of things far away then this might actually be to your advantage. But if you want to use a wide-angle lens then this cropping
factor can be a problem, since wide-angle lenses yield less dramatic results when you crop out the edges.
Some people object to the term cropping factor as well, arguing quite rightly that the issue is a matter of a change in format of the image recording area and using
lenses designed for a different size format. This is true, but people are so used to equating a given 35mm film focal length with a given coverage area (or field of view)
that I think the concept of a cropping factor is convenient and easily understood.
To give an example, let’s say you have a 100mm lens. When used on a 35mm film camera you get a certain coverage of the scene. But if you were to put the same
lens on a digital camera with a 1.6x crop factor (ie: a smaller than full frame sensor) then you would not get the same view of the scene - you’d get less. The view you
would see on your 1.6x digital camera would be the same as if you had a 160mm lens, were there such a thing, on your 35mm film camera.
There’s dust inside my lens!
Unfortunately that’s pretty normal. Only certain expensive L series lenses are sealed to prevent air from entering. All others have a lot of cracks and openings where
air - and dust - can easily enter. Zoom lenses which extend in length when you alter the focal length are particularly vulnerable to this problem, since air gets sucked
in every time you move the lens barrel.
Luckily a little bit of dust inside a lens isn’t going to make much difference, so don’t worry about it. It may be alarming to see the dust specks when you hold the lens
up to a bright light, but it’ll cost an awful lot of money to have a camera repairperson dismantle the lens and clean each internal element. And there’s no guarantee
that the elements will be properly aligned when he or she gives it back to you. So unless the lens is coated with a dusty grey film of dust you shouldn’t have any
problems.
There’s a scratch on the front glass of my lens!
A tiny scratch or chip on the front glass of a lens, alarming as it may look, won’t actually make much difference in image quality under most circumstances since it’s
far enough from the film or image sensor plane not to be in focus. It can, however, affect lens flare, so it’s usually worth filling in the chip with black pen. Having said
that, a large chip (more than a few millimetres long) is obviously undesirable. And chips on the rear glass of a lens are more of a problem.
I’ve seen ads for teleconverters or extenders. Can I put one of these onto my, say, 50mm lens and magically turn it into a 100mm lens?
Yes and no. The answer to this is complicated, but leans mainly towards the “no” side.
Teleconverters, called “extenders” by Canon, are optical accessories which fit between the camera body and the lens. They’re essentially tubes with a few glass lens
elements inside which multiply the focal length of the lens in use - typically by 1.4x or 2x. So a 50mm lens with a 1.4x teleconverter (TC) would take the same
photographs as a 70mm lens, and a 100mm lens with a 2x TC. Think of TCs as magnifying glasses - they enlarge the central portion of the image and cut off the
periphery.
Unfortunately you can’t get something for nothing. And in the case of TCs there are three major tradeoffs.
First, using a TC cuts the amount of light entering the camera. A 1.4x TC costs you a stop of light and a 2x TC costs you 2 stops. This is particularly problematic if
you have a slow lens. Since most Canon cameras (pro cameras notwithstanding) can’t autofocus with lenses slower than f/5.6 you may lose autofocus, or at least
reliable autofocus, if you use a TC. You can sometimes get around this by taping over the teleconverter’s extra pins, thereby fooling the camera into thinking there
isn’t a TC on it at all, but obviously that’ll only really work if there’s enough light coming into the camera for the autofocus mechanism to function. Manual focussing
will also be difficult if the view through the viewfinder is dark, as it will be with slower lenses.
Second, there’s the question of compatibility. Canon manufacture two teleconverters - Extender EF 1.4x and Extender EF 2x - but they are specifically designed to
work only with the handful of expensive telephoto lenses listed below. These extenders have protruding front elements and so physically can’t attach to most EF
lenses - the protruding element simply gets in the way. You could work around it by sticking an extension tube between the TC and the lens, but this would cut even
more light and would also mean you lose infinity focus.
You can avoid this problem by eschewing Canon and going third-party for your TCs. Tamron and Kenko sell their own TCs which don’t have these protruding
elements and so can physically mate with any EOS lens (though TCs in general don’t work very well optically with lenses which aren’t telephotos). These third party
TCs come in varying levels of optical quality. The better quality (more expensive versions, such as the Kenko Teleplus Pro 300 DG) models are generally held as
having decent optics, though not quite as good as the Canon products.
Third, all TCs degrade image quality somewhat. First, you’re adding a bunch more glass between you and the scene you’re photographing and second, you’re using
only part of the centre of your lens. 2x TCs enlarge more of the middle of the lens than the 1.4x TCs, which makes 2x converters worse optically. Now, in the case of a
fancy Canon L series lens and a Canon Extender, this optical degradation will be fairly minimal. However, if you take your typical cheap consumer zoom lens and slap
a third-party TC on it you’ll find that the results will be less than stellar. In fact, in such cases you’re probably better off simply cropping and enlarging part of a photo
taken without a TC and leaving it at that. The quality would be higher and you’d save money.
So. The answer to this question really depends. If you have a professional lens and a quality TC then, yes, you’ll be able to increase your focal length at the cost of
some light. But if you have your typical consumer lens then there’s probably no point buying a TC - you’ll end up with fairly crummy photos.
Canon extender compatibility list:
The Canon extenders are physically compatible with all prime (fixed focus) Canon EF lenses with a focal length of 135mm or longer except for the 135mm 2.8 SF.
They are also compatible with a handful of recent L series zoom lenses. The full official list is:
• 70-200mm 2.8L
• 70-200mm 2.8L IS
• 70-200mm 4L
• 100-400mm 4.5-5.6L
• 400mm 4 DO
• 135mm 2L
• 180mm 3.5L Macro
• 200mm 1.8L
• 200mm 2.8L
• 300mm 2.8L IS
• 300mm 4L
• 300mm 4L IS
• 400mm 2.8L IS
• 400mm 5.6L
• 500mm 4L IS
• 600mm 4L IS
• 1200mm f/5.6L
Consult Canon when checking out newer L series lenses introduced since this list was written, and you’re on your own if you use third party lenses. You can also use
Canon extenders with Canon TS (tilt-shift) lenses, but it should be noted that the TS lenses can’t report to the camera that the extenders are there.
Auto focus is not supported by non-pro EOS cameras when the 1.4x converter is used with 100-400mm 5.6L, 400mm 5.6L, 500mm 4.5L, 1200mm 5.6L, and with the
180mm 3.5 Macro when it’s focused closer than 0.8 meters, or when the 2x converter is used with the 70-200mm 4L, 100-400mm 4.5-5.6L, 180mm 3.5L Macro,
300mm 4L IS, 300mm 4L, 400mm 4 DO, 400mm 5.6L, 500mm 4L, 500mm 4.5L, 600mm 4L, and the 1200mm 5.6L.
Note that there are two generations of the Canon Extenders - the original 1.4x and 2x models and the mark II successors, which add improved weatherproofing. The
1.4x II is said to be optically identical to its predecessor but the 2x II has minor optical enhancements.
I want to take close-up (macro) photos. What do I need?
Close-up or macro photography is a lot of work, but it can also be extremely rewarding. Detailed close up photos of tiny objects can literally introduce you to another
world. Here are some reasons why it’s a very challenging area of photography.
• Most camera lenses are not capable of focusing close enough to take decent macro photos. Even lenses marked “MACRO” can’t necessarily be used for
interesting macro photography - see the section above.
• The close-up exposure mode (indicated by a flower icon) on most EOS cameras does not really help macro photography at all. All it does is set certain
camera characteristics, such as metering method and motor-wind settings, to make macro photography slightly easier. The icon mode does not alter the lens
characteristics in any way.
• As noted above, depth of field is incredibly shallow when it comes to extreme closeup photography. This means that your focusing has to be absolutely
dead-on.
• The usual solution to excessively narrow depth of field problems is to stop down the lens. The problem with that in macro photography is that stopping down
the lens limits the amount of light coming into the camera, which can cause problems with lighting.
• In fact, since working distance (the distance between the end of the lens and the subject) is often really limited, lighting is usually a problem even if you
don’t stop down a lot. Simply because the lens itself blocks a lot of light. For that reason flash units are a very common macro photography accessory, particularly
ring-shaped flash units which fit around the end of the lens itself. Such macro ring light flash units often have two tubes so you can control the relative brightness of
one side of the image compared to the other. If you’re on a really tight budget, however, you could try putting a translucent white milk jug around lens and shining
really bright light onto it.
• Unfortunately, auto focus often doesn’t work very well if at all under macro conditions, particularly if you’re using an extension tube. A camera with a
manual focus assist aid in the viewfinder screen is a useful accessory, as is a magnifying attachment for a viewfinder so you can see the camera’s focus screen more
clearly.
• Focusing is often so tricky that experienced macro photographers don’t adjust focus using the manual focus ring on the lens. Instead they physically move
the camera closer to or further away from the subject in order to focus. You can buy convenient adjustable rail systems (macro focus rails with one or two rails) that
slide the camera back and forth for this type of precise macro focussing.
• When you’re dealing with closeup work the tiniest motion is magnified. Let’s say you’re shooting a spider’s web on a misty morning; the dewdrops
clustered on the threads like tiny glass spheres. The problem is that the gentlest breeze can set the entire web bouncing, quivering and vibrating so badly that you get
motion blur. This is also why you typically need a tripod to do it right. Handholding a camera introduces too much camera blur unless you use a motion-stopping burst
of light from a flash unit.
Here are your six basic choices if you want to take a closeup photograph.
1) Buy a true macro lens capable of reaching 1:1 magnification.
(see the previous section for an explanation of 1:1 magnification) This is the most expensive option, since true macro lenses aren’t cheap. However, it’s usually the
most high-quality option. True macro lenses come in a variety of focal lengths, from 50mm to 90 or 100mm to 180mm. The advantage of the longer lenses is that they
give you more working distance from your subject. A 50mm macro lens isn’t very useful for shooting, say, dragonflies in the wild since you have to be really close to
them. A 180mm macro lens, on the other hand, lets you maintain more distance so you’re less likely to frighten them off. Of course, 180mm macros are pretty
expensive. A 90/100mm lens is usually the better compromise in terms of working distance and cost.
There are six true macro lenses in the EF lineup which can do 1:1. There is the 50mm f2.5 Macro (which technically only goes to 1:2 or half-size and requires the
optional Life Size Converter EF to reach true 1:1), the discontinued 100mm 2.8 Macro, the newer 100mm 2.8 Macro USM, the expensive 180mm 3.5L Macro USM
and the EF-S 60mm 2.8 macro, which only fits EF-S-compatible cameras. There is also the unusual MP-E 65mm lens; see below. Another popular macro lens worth
considering, though not from Canon, is Tamron’s 90mm macro lens.
2) Buy a diopter (macro filter).
These are round screw-on lenses which fit on the end of a lens in exactly the same way as a filter and which act essentially like magnifying glasses. The amount of
magnification you get depends on both the strength of the diopter and the focal length of the lens to which you attach it. Diopters cost no light but can degrade the
image slightly, depending on the quality of the product. Still, they’re lightweight and portable and, since they cost no light, usually permit autofocus to work. They’re
usually a good approach for beginners looking to explore macro photography.
You can buy both single-element diopters which contain a single piece of glass and two-element diopters which contain two. Two-element diopters are what you want -
they cost more but provide vastly better optical quality by correcting certain optical aberrations. Diopters are available in a variety of physical sizes which match
popular lens filter sizes, but can be adapted with step rings just like ordinary filters if necessary.
Canon sell two two-element diopters - the 250D and the 500D. The former is intended for shorter focal length lenses, from about 30-135mm. The latter is meant for
longer focal length lenses, from about 70-300mm. You can also buy a 500 diopter which, since it’s a single-element accessory, isn’t as good. You don’t have to buy
Canon’s diopters, of course - Nikon also sell highly-regarded diopters (the Nikkor 3T, 4T, 5T and 6T closeup attachments) which are actually usually less expensive
than Canon’s. Bob Atkins’s Web site has a comprehensive table of magnifications available using different diopters on different lenses.
3) Buy an extension tube.
These are hollow plastic tubes which fit between the lens and the camera body, thereby increasing the distance of the lens to the camera and thus reducing the close
focus distance of your lens. (ie: they let you move the lens closer to the subject while retaining focus) Attaching an extension tube means you lose infinity focus but
that’s obviously not an issue if you’re using the tube to take closeup pictures. Tubes also reduce the amount of light reaching the film or image sensor (because
moving the lens further from the film or sensor plane causes the light to spread out across a larger area).
Unlike diopters, however, they do not affect image quality at all as no optics are involved. The magnification you get depends on both the length of the tube or tubes
used and the focal length of your lens - Bob Atkins’ table lists some common combinations. Some lenses, particularly wide-angle and specialized lenses such as the
15mm 2.8 fisheye, 14mm 2.8L and MP-E 65mm 2.8, don’t work properly with tubes. If you have EF-S lenses for newer EOS digital cameras then you’ll need the mark
II Canon extension tubes (the Extension Tubes EF 12 II and EF 25 II), since the earlier versions don’t mate with EF-S lenses - EF-S lenses extend deeper into the
camera body than EF lenses.
Canon sell a couple of extension tubes, but they’re pretty expensive. The three-tube set from Kenko is a better deal - it’s fairly well made and contains a 12mm, a
20mm and a 36mm tube. However, current Kenko tubes are compatible only with EF lenses - they do not physically mate to EF-S lenses.
Adjustable bellows are also used for closeup photography - they’re basically adjustable tubes when you get down to it. Novoflex sell an EOS-compatible bellows or
you could buy the old Canon FD bellows and adapt it using the FD to EOS macro adapter. Bellows are typically used with movable rails for precise focussing.
4) Reverse a lens by mounting it onto the camera backwards.
Doing so requires some sort of adapter with a standard EOS lens mount on one end and a filter ring on the other which attaches to the filter ring of the lens. People
often make such things at home by gluing a filter ring to a drilled-out body cap. Reversing a lens like this is a very old photographic trick for doing macro
photography.
This technique is a problem for EOS lenses, however, since EOS lenses require electrical connectors in order for the aperture diaphragm to operate. There are at
least three possible solutions for this. First, you could set the lens aperture to whatever you want it to be, press the depth of field button on your camera to stop down
the lens and then detach the lens. The lens diaphragm should stay wherever it was when you removed the lens and you can then reverse the lens and use it. This isn’t
terribly convenient, of course, since you can’t adjust the aperture without remounting the lens. Second, you could use a non-EF lens. Any 35mm lens will do, really,
since you’re mounting it backwards and not using the normal lens mount. Third, you could buy Novoflex’s rather expensive lens reversal adapter, which contains the
necessary wires and connectors to let the electromagnetic diaphragm operate correctly.
5) Attach a reversed lens to an existing lens.
Another old macro trick is to attach a 50mm (normal) lens to the end of another lens, but backwards. (ie: the filter threads of the 50mm lens are attached to the filter
threads of the camera-mounted lens by means of a special lens-reversing or macro-coupling ring) You won’t be able to adjust the aperture of the reversed lens if it’s
an EF-type lens, but there’s nothing stopping you from using a non-EOS lens in this way, as above. A 50mm lens reversed on a 100mm lens can give you 2x
magnification, for example, albeit with a fair bit of light loss.
6) Buy the Canon MP-E 65mm lens.
This is an unusual and specialized lens that’s designed solely with macro photography in mind. It can’t be used for normal photography, unlike the other Canon macro
lenses, as it starts out at 1:1 magnification. It goes from there to 5:1 magnification. At this magnification an object 5mm x 7mm in size will fill the entire frame of
35mm film.
Though intriguing, it has a number of drawbacks. First, you can use it for super closeup photography and nothing else since it lacks infinity focus. Second, it suffers
from the usual problems of macro photography - very narrow depth of field and the difficulty in illuminating objects adequately given the short working range. Third,
ambient light metering works only with EOS 1 series cameras - all other EOS cameras can only be used with TTL flash metering. And fourth, the focussing screen of
your camera may not be precise enough for accurate focussing.
Can I use the Canon 100mm macro lens for portraits?
Absolutely. The 100mm 2.8 macro and macro USM lenses are both excellent portrait lenses in addition to being great macro lenses. The only problem is that they’re
extremely sharp lenses, and some people prefer softer lenses for portraiture, particularly of women. If you’re in that camp you could always slap a soft focus filter
onto the lens.
What happened to the solid all-metal lens barrels of yesteryear? Why is everything today made of plastic?
It’s true that a lot of lens barrels of the 60s and 70s were solid finely-crafted metal masterpieces with smooth focussing spiral-shaped helicals and precisely-machined
parts. Whereas today many lens barrels are made largely of plastic. There are a number of reasons for this - the rise of autofocus, rise in labour costs, lower SLR
sales, improved plastics technology, a desire to make lighter-weight gear, increased profit margins for manufacturers and so on.
Certainly the rise of autofocus is a major factor. Autofocus lenses with geartrains (ie: ring USM lenses excepted) require a bit more looseness and play in the
geartrain system. They also don’t usually use long focussing helicals as that would take more battery life and time to focus. Manual focus lenses with helicals, by
contrast, can be machined to very tight tolerances.
However, there are advantages to increased use of plastics in lens construction. Quality plastic is fairly resilient and doesn’t dent like metal, plastic is obviously much
lighter than metal, plastic components are less expensive to produce and can in theory result in lower prices to the consumer and so on.
So, while the old manual-focus lenses may feel great to hold and use and exude that terrific sense of precise quality that plastic lenses simply do not do, it’s unlikely
that less expensive autofocus lenses will ever be made with metal barrels. Note, however, that many Canon L series lenses use solid metal barrels and have
reasonably tight-feeling manual focus rings. So if you’re willing to spend the money you can still get metal lenses and retain autofocus.
Grades of plastic
There’s also plastic and there’s plastic. Canon have used, very roughly speaking, three different grades of plastic shell material for their EF lenses over the years.
The first generation of EF lenses used a fairly brittle hard type of plastic, which I call type 1. (though that isn’t, of course, an official Canon designation) This material
was moulded with a slight rough texture and the lenses had basically parallel lines to their cylindrical barrels, with little if any tapering. Focus and zoom rings often did
not have rubberized surfaces. The 50mm 1.8 mark 1 is an example of this late 80s type of design. In my experience, though this purely anecdotal, type 1 plastic is a bit
more likely to crack upon impact than later plastics.
The second generation, particularly black L lenses and advanced amateur lenses, are made of a more resilient hard black plastic, which I call type 2. These lenses
have relatively little texture - they’re either quite smooth or have a subtle hammered finish. These barrels tend to have subtly tapered barrels rather than simple
cylinders, and have rubberized zoom and focus rings. The 28-105 3.5-4.5 USM is an example of a midrange zoom of this construction, and the heavier 135mm 2.0L
USM is an example of an L lens using this construction, albeit with thicker plastic and a generally sturdier design. Lenses of this type first came out in the early
1990s, and seem to me to be slightly less likely to crack upon impact - the plastic has a tiny bit more inherent flex to it.
Finally, inexpensive cheapie lenses over the past few years have been made of lightweight smooth plastic which I characterize as type 3. These lenses often have
somewhat exaggerated rubber rings for zoom grips, and later models (late 90s on) have shiny chrome rings around the end to impress less experienced consumers.
The EF-S 18-55 3.5-5.6 is a typical example of this type.
Lens-related technical terms and vocabulary.
What is focal length?
The focal length is a basic optical property of any lens, and the most important one to a photographer. The simple way to think of the focal length is to think of it as a
numerical value, expressed in millimetres, which represents how much of a given scene (the coverage area) a lens can take in.
Focal lengths for Canon SLR lenses range from ultra-wide (14mm) to incredibly long telephoto (600mm and 1200mm). The typical range of an affordable lens or
lenses is from 28mm to 105mm or so.
Why, then, these strange values in millimetres? Why not indicate the angle of view taken in by each lens instead? Well, partly for historical reasons and partly for
practical reasons. The technical description of focal lengths is rooted in the mathematics of optics - it’s the distance between the focal plane and the rear nodal point
of the lens, given infinity focus. How this bit of Martian translates to the field of view depends on the size of the imaging area being used, which can be different
between 35mm film cameras, APS cameras and some digital cameras. And as for practical reasons, the focal length of a lens is an innate property of the lens, but the
actual coverage area of the scene depends on the size of the image format used.
So note that crucial point - all the examples I gave above are for a 35mm film camera or full-frame EOS SLR only. If you were to use a 28mm lens on an APS camera
or a digital camera with an image sensor smaller than that of 35mm film (ie: most digital cameras sold today) then you would have a much narrower field of vision than
if you were to use the same lens on a 35mm film camera. For more details see the section on focal length multipliers/cropping factors.
The same focal length system is used to describe lenses for other types of cameras as well, such as medium format cameras. But the area taken in by a lens on a
medium format camera will be totally different from that of a lens of the same focal length on a 35mm camera, because the area covered by medium format film is
considerably larger.
What is a lens aperture or f stop?
The aperture of a lens is its second most important optical property after its focal length. Consider the human eye. It has a coloured iris with a pupil which can dilate
or contract in order to let in more or less light, depending on ambient light conditions. When it’s dark the pupil opens up to let in as much light as possible. And when
it’s sunny the pupil contracts to prevent the bright light from overwhelming the eye. Most camera lenses have a device analogous to the iris - a metal or plastic
diaphragm which can be adjusted in size to control the amount of light entering the lens.
The variable-sized hole in the diaphragm is known as the aperture, is analogous to the pupil of the eye, and is indicated numerically by an f-stop or f-number value.
This value, the relative aperture of a lens, describes the amount of light that a lens lets in. The value is relative because it is equivalent to the focal length of the lens
divided by the size of the lens aperture, not the physical dimensions or anything.
For example, if you were to take a 50mm lens with a 6.25mm diameter aperture you’d have a lens set to f/8 (since 50/6.25 = 8). Generally each increase or decrease in
f-stop value either doubles or halves the aperture size. Since f-stop values are relative to the focal length, each camera lens should let basically the same amount of
light through at the same f-stop value regardless of focal length. (barring complex technical factors such as light loss from large numbers of elements and so on, but
we won’t get into that here)
The usual f-stop range on 35mm and digital SLR camera bodies is:
1.0 1.4 2 2.8 4 5.6 8 11 16 22 32
though most camera lenses are only optically capable of a subset of that overall range.
The relationship between these values involves halving and doubling the amount of light. Going from f/2.8 to f/4, for example, involves a halving of the aperture size.
Each number is approximately 1.4x more than its previous stop since 1.4 is the square root of 2 (to one decimal place), though since the specific numbers derive from
tradition they are not always spot on. Lenses for larger camera systems such as large format cameras usually have even smaller apertures - going to f/64, for
example.
This series of numbers may look difficult to work with, but in fact there’s a fairly simple way to recall it. Just remember that the first two values are 1.0 and 1.4
respectively. Each following value then doubles by every other value. So 1.0 becomes 2, then 4, then 8 and then 16. 1.4 becomes 2.8, then 5.6, 11 and 22. (the only
minor glitch, of course, to this handy mnemonic scheme is between 5.6 and 11)
Confusingly enough, when the number is small (eg: f/2.8) then the lens diaphragm is open wider (“opened up”) and thus more light enters the lens. If the number is
large (eg: f/22) then the lens diaphragm is closed smaller (“stopped down” or “closed down”) and thus less light enters the lens. In addition to altering exposure times,
the aperture setting also affects depth of field.
The letter f is frequently italicized for good looks, and a slash is often placed between the letter f and the numerical f stop value to indicate that the f-stop value is a
fraction of the focal length. eg: f/4 means that the aperture is a quarter of the focal length. The letter f stands for “focal,” “factor” or “focal length” depending on who
you talk to, and the number is also often stated as a ratio. (eg: 1:2.8)
Note that not all lenses have adjustable diaphragms. Many types of lenses, though not usually those sold for use with EOS cameras, have fixed apertures. Mirror
lenses, for example, fall into this category since they lack (adjustable) diaphragms. Really crummy cameras - disposable cameras being one example - also have fixed
apertures. These two examples aside, however, nearly all lenses sold for use with EOS cameras have adjustable apertures.
What is a slow lens or a fast lens?
These are colloquial expressions describing the maximum aperture value or values of which the lens is capable. Slow lenses have a very small maximum aperture,
which means less light enters the lens and so longer time periods are required to expose the film or image sensor. Fast lenses have a very wide maximum aperture
and so shorter time periods are required to expose the film or image sensor.
The larger the maximum aperture of a lens the more light it lets in. And so faster lenses are generally more desirable than slower lenses. First, fast lenses let you
take photos in lower light levels using available light rather than blasting the scene with ugly light from a flash unit. Second, you can see through the viewfinder better
since fast lenses let in more light and so the view through the finder will be brighter with a fast lens.
As explained above, lens f stops are ratios, and so smaller numbers indicate larger apertures. A lens with a maximum f stop value of 1.4 is, therefore, fast. And a lens
with a maximum f stop value of 5.6 is slow by comparison. However, f stop numbers are the ratio between the focal length of the lens and the aperture, which means
that it’s very easy to design a fast 50mm lens (1.8 is a typical maximum aperture value) but very hard to design a long 200mm telephoto lens with a maximum
aperture so large.
In fact, designing fast lenses in general is more complex and expensive than designing a lens with a small maximum aperture, so fast lenses tend to cost more than
slow ones. It’s also harder to design and build a fast zoom lens than it is a fast prime (fixed focal length) lens. Faster lenses are also usually physically larger than
slower lenses of equivalent focal lengths. The reasons for all this are tied into the complex mathematics of optics.
Note that autofocus lenses for EOS cameras have the focus motor built into the lens, not the camera. And some lenses focus more rapidly than others. So sometimes
you hear people talking about a lens having a fast or slow focus motor speed, which is a separate matter altogether from the optical properties of the lens.
What is depth of field?
When you focus on something, the subject isn’t the only thing that’s going to be sharply focussed. Certain objects closer to you and further away from that subject will
also be in acceptable - though not quite as sharp - focus. The distance range within which these objects appear to be in reasonable focus in your final photograph is
known as depth of field. Being able to control depth of field is an important photographic skill since it can affect the appearance of a photograph dramatically.
For example, let’s say you’re taking a portrait of someone outside. And let’s say that the reason you’re doing so outside is to get nice natural lighting, but you don’t
care so much about the background as such. Maybe you’re in a park and you don’t want to show a cluttered background of trees, grass and bushes. In this case you’ll
want a narrow depth of field and focus on the person’s eyes since they’re the key thing you want to have in focus. If you have a narrow depth of field then the
background will be thrown nicely out of focus and you’ll just have a pleasingly blurry green background to your portrait.
But let’s say you want to take a nature photograph of a flower in a dramatic mountain landscape with an interesting sky. In this case you’ll probably want everything
from the flower to the sky to be sharply in focus. This would require great depth of field.
There are three factors which control depth of field on a given camera. They are as follows:
Aperture.
The aperture (f stop) to which a lens is set is a very important factor governing depth of field. The larger the aperture (smaller the f stop number) then the smaller the
depth of field and vice versa. So if you’re shooting something in low light conditions and open your lens up to f/1.8 in order to admit as much light as possible you’ll
find you have a really narrow depth of field, which can be a real problem sometimes, since precise focussing is required. Conversely if you’re shooting outdoors on a
bright sunny day you may find you’ll need to stop down a long way to get the shutter speed you want, but this can result in too great a depth of field for some
applications.
Focal length.
The focal length of your lens also makes a tremendous difference. Lenses with short focal lengths (wide angle lenses) have wider depths of field available and lenses
with long focal lengths (telephoto lenses) have shallower depths of field available. This is generally a good thing. If you’re using a really wide lens for landscape shots
you’ll be able to get huge areas of scene in sharp focus. But if you’re using a really long telephoto lens for bird photography then your depth of field will be really
shallow and you’ll be able to isolate the bird in the landscape nicely.
Subject distance.
Finally, the distance from the lens to the subject also affects depth of field. If you’re really close to your subject, such as in macro photography, then depth of field will
be shallow. But if you’re taking a photo of something that’s a long way away then your depth of field will be deeper.
Naturally all three of these factors work together, so you can adjust all three factors to achieve the effect you’re looking for.
It should be noted that the size of a camera’s image area also dictates the depth of field. A camera with a large image area - say a medium-format or large-format
camera - is capable of a much more shallow depth of field than a camera with a smaller image area. This is why consumer digital cameras, which have tiny image
sensors, have such deep depth of field. However, you can’t change this particular factor without switching cameras. The other three factors above are adjustable on
any given EOS camera.
It should also be noted that this is a very non-technical description of what depth of field is all about. To be more accurate about it you need to go into a lot of math
and a definition of the circle of confusion and a consideration of the print size and so on. But the simplified stuff above is adequate to get a grasp of how to control
depth of field adequately to make your photos look the way you want them to.
What is a bayonet mount?
Canon EF mount lenses are of the “bayonet” type. This means that the lenses have mounting lugs (three in the case of EOS lenses) which slot into the camera body
mount. You then rotate the lens a partial turn to lock it into place with a click.
Most camera makers these days use bayonet-style mounts, though other types were popular in the past. For instance, older Pentax and Leica cameras used
screwmount systems - you simply screwed the lens into the camera body’s threaded mount. The lens system used by Canon prior to the introduction of EOS was the
FD system, which used a “breechlock” mount system with a rotating friction ring.
Lens hoods often fasten by means of bayonet mounts. Some filters for certain European lenses also use bayonet mounts, though Japanese makers generally use
threaded filter mounts.
It’s not clear why the lens mounts are called bayonet mounts. The two theories I’ve heard both stem from bayonets, the knives which soldiers fasten to the end of
their rifles. One theory, which is probably utterly apocryphal, suggests it’s a gruesome joke deriving from the instructions given to soldiers on how to use their
bayonet - thrust in and twist. The more probable and prosaic theory is that the term derives from the design of bayonet mounts on rifles.
What does a Roman numeral on a lens refer to?
Canon, like most Japanese lens makers, use the optical specifications of a lens to distinguish one model from another. (European makers have traditionally come up
with fun names resembling Star Trek planets, like “Tessar,” “Biogon” or “Super Angulon,” to describe their lens designs) But sometimes a maker will produce new
models later on which happen to have the same basic specifications as previously-made ones. To distinguish these lenses one from another Canon will add a Roman
numeral to the end of the lens specification, starting with II. For this reason you will never see a lens marked with a I, though people often refer to “mark I’” lenses
when subsequent models are released. You will, however, see lenses marked with II, III, IV, etc. These are commonly referred to as mark II, mark III, etc, lenses in
common parlance.
Sometimes these later lenses are an improvement over the original, sometimes they’re worse and sometimes they are almost identical bar some cosmetic changes.
For example, the 50mm 1.8 II is markedly inferior to its predecessor in build quality but has the same great optics, the 28-80 3.5-5.6 USM II is entirely worse in every
respect to the mark I edition, but the 28-105 3.5-4.5 and 28-105 3.5-4.5 II lenses are basically the same with slight cosmetic differences. There’s unfortunately no way
to tell from the Roman numeral designation itself whether or not a later lens is better or worse. I try to identify these differences between versions in my lookup page,
so that’s a good starting point.
Canon also release updated versions of lens hoods using Roman numeral designations, as described above.
What is the difference between the various kinds of lens motors (AFD, MM, USM)?
Unlike most camera makers Canon chose to position the auto focus motor inside the lens barrel rather than in the camera body when they designed the EOS system.
This was arguably a wise move, since it means auto focus motor can be tailored to the requirements of each lens. A big telephoto lens can have a large motor and a
small normal lens can have a more compact motor. By contrast, systems which rely on the auto focus motor being only in the camera body don’t have this flexibility -
the motor is always the same regardless of the lens used unless you change camera bodies.
So. Canon employ a number of different motor technologies in their lenses. The first two types are never identified specifically on the exterior of the lens. You have to
look up in Canon’s product literature to see which type of motor a given lens uses.
Traditional electromagnetic motor drives.
Such motors contain tiny wound coils of wire and rely on electromagnetic principles to turn a shaft. Little cogwheels and gears are then used to translate this
rotational motion into the movement needed to adjust lens focus.
Arc-form drive (AFD).
Generally used in a number of older lower-cost lenses, AFD motors are simply little electric motors which drive a geartrain. They’re somewhat noisy - electric buzzing
and grinding of gears - and not terribly fast. This isn’t a big deal on smaller lenses since the distances the motors must move the focussing elements aren’t very far.
However, telephoto lenses with AFD motors can be quite sluggish.
Micromotor (MM) drive.
Generally used on a few older lower-cost lenses. Similar to AFD - slow and noisy and based around an electric motor driving a geartrain. Some particularly low-cost
lenses use micromotor drives with rubber belts.
Ultrasonic motors.
Ultrasonic motors do not rely on magnetic coils like most electric motors. Instead they use extremely high-frequency vibrations which translate into circular motion.
The result is a very fast and pretty well silent (to human ears, anyway) lens motor. There are two basic types employed by Canon.
Ring ultrasonic (USM) drive.
The kind you want. These motors consist of two metal rings which vibrate at a very high frequency. (have a look here for photos of these rings) Ring ultrasonic lenses
are great because they focus quickly and silently and also support full-time manual (FTM). There are actually two variants of this design - see the FTM section
below.
Micromotor ultrasonic (USM) drive.
This kind is less desirable. It’s a form of USM motor that Canon designed for their cheapie lenses so they can bill them as ultrasonic for marketing purposes. An MM
lens replaces the standard magnetic motor with an ultrasonic motor but retains the usual geartrain setup. Such lenses are still reasonably quiet, though not as quiet as
ring ultrasonic motors, but usually lack FTM - see below.
Note that, while all lenses with “USM” in the name contain an ultrasonic motor, Canon do not distinguish between ring and micromotor USM drives in the name - you
have to look up the specs for the individual lens to find that out. Also, most non-L lenses with USM drives have striped gold lines painted around the end of the barrel.
However, all L lenses have red lines painted around the end, whether or not they use USM (ie: Canon never have two painted rings around their lens barrels, and the
red L line takes priority over the gold USM line).
What is full-time manual (FTM)?
As noted above, Canon EF lenses with AFD (arc form drives) and MM (micromotor) drives use very simple autofocus mechanisms which rely on electric motors and
geartrains - rows of tiny cogwheels. Unfortunately, turning such a focus system by hand can damage the geartrain, so such lenses have a switch mechanism which
disengages the cogwheels when you focus manually. There is thus no way for you to focus manually when the lens is switched over to autofocus mode.
However when Canon introduced lenses with USM (ultrasonic motor) autofocus systems they also introduced full-time manual focussing (FTM). Such lenses allow
you to adjust focus manually even when the AF/MF switch is set to autofocus. This is very handy, as it lets you adjust or touch up focus without having to flip the
switch.
There are a few points to keep in mind here.
• There are actually three different types of USM motors, although there’s no way to distinguish them apart by looking at them - the lenses are all simply
marked “USMThe best USM motors are those used in most midrange and L series contemporary lenses - ring USM motors. A ring USM motor consists of two metal
rings which vibrate at high frequencies, resulting in rotational energy. Full-time manual on a ring USM lens is easy - there’s a simple friction clutch which means
you’re simply turning the whole motor by hand when you rotate the focus ring. This means you can focus the lens manually at any time, even if the camera is turned
off or the lens isn’t attached to a camera.
• The second type of USM is the earliest design, and seen only on a few older lens designs and some longer telephotos. These are electronic focus ring USM
lenses which can only focus manually when the camera is actually turned on. This is because turning the focus ring sends electronic commands to the lens motor,
ordering it to rotate. The following lenses are old-style electronic full-time manual USM lenses:
EF 50mm 1.0 L USM
EF 85mm 1.2 L USM
EF 85mm 1.2 L USM II
EF 28-80mm 2.8-4 L USM
EF 200mm 1.8 L USM
EF 300mm 2.8 L USM
EF 400mm 2.8 L USM
EF 400mm 2.8 L II USM
EF 500mm 4.5 L USM
EF 600mm 4 L USM
EF 1200mm 5.6 L USM
• Finally, there are micromotor USM lenses. These are mostly inexpensive consumer lenses which do not support full-time manual, because they still use a
mechanical geartrain. Arguably these lenses are barely USM, since the only real advantage they have over regular motors is that they’re slightly quieter.
There are a couple of exceptions to confuse matters, however. The 50mm 1.4 USM and the newer 28-105 4-5.6 USM lenses contain slip clutch mechanisms which let
you use FTM in a fashion similar to a ring USM lens.
• Adjusting focus manually is a bad idea when the lens motor is in the process of turning, since you’d be fighting the motor and straining it. Wait until the lens
motor has stopped operating before turning it by hand.
• Finally, adjusting focus manually is also a bad idea when the camera is in AI Servo mode, since the AF motor can kick in at any time.
Do USM lenses take better photos than non USM lenses?
No. USM (ultrasonic motors) are autofocus mechanisms. They in no way affect the optical quality of a lens.
Of course, since USM lenses focus faster and more quietly than non-USM lenses there’s the possibility that using one might help you get a photo that you might not
have got with a slower or louder autofocus lens. But that again is unrelated to the optical quality itself.
This confusion may come in because Canon only put ring USM drives into their midrange and pro (L series) lenses. You can’t buy cheap Canon lenses with ring USM
- only micromotor USM (see above). But again this is no guarantee of anything, since there are plenty of Canon lenses - particularly their older prime lenses - which
lack USM but which have excellent optical quality.
What is image stabilization?
Image stabilization or IS is a Canon technology that optically corrects for camera motion when you take a photo. Since camera motion - caused by handholding the
camera, for example - can result in blurring of the image at slower shutter speeds, IS can result in sharper photographs when fast shutter speeds are not possible.
IS is a fairly complex technology involving motion sensors, microcomputer chips and small motors to move key lens elements. There is, therefore, a price premium for
IS-capable lenses. But they can be very convenient - when handholding a camera you can easily gain a stop or two over using a non-IS lens.
However, remember that IS does not increase the maximum aperture of the lens or anything. An IS lens with a maximum aperture of 3.5 still has a maximum aperture
of 3.5. IS simply lets you use a slower shutter speed than would otherwise be possible when you’re handholding the camera, by compensating for camera motion. So
you won’t necessarily be able to get that narrow depth of field that you could with a faster lens - which could be a drawback or a benefit depending on your point of
view.
IS has a few other drawbacks over faster lenses as well. Earlier IS lenses tended not to perform very well when mounted on a tripod when the IS mechanism was
engaged. Consumer IS lenses also do not work very well when panning (tracking a moving object), though pro IS lenses do. IS does not help you if the subject is
moving - it compensates only for camera motion. IS doesn’t help freeze subject motion and in fact will probably make things worse by letting you use a much slower
shutter speed than a fast lens. Some people find the slight swimming motion in the viewfinder when using IS a bit dizzying and IS uses a little more battery power than
no stabilization at all. Finally, some earlier film EOS cameras are not entirely compatible with IS lenses and have minor inconveniences, such as viewfinder shake
once a photo has been taken (though this does not affect the picture quality).
Nonetheless, these drawbacks aside, most people find IS quite valuable, particularly on long telephoto lenses.
Canon were the first company to include image stabilization technology in SLR lenses, though Nikon actually pioneered the field with a stabilized-lens point and shoot
(the Zoom-Touch 105 VR) in 1994. Today Nikon sell a range of VR (“vibration reduction”) SLR lenses; the main difference being Nikon sell mainly to the high end
lens market where Canon sell a variety of IS lenses covering the mid to high end markets. Sigma have also released a number of image-stabilized lenses. Canon IS
technology is built into the lens, like the Mega Optical Image Stabilizer (Mega OIS) system used by Panasonic. These both differ from the Minolta-developed Super
SteadyShot stabilization technology used by Sony, which is built into the camera body. Building anti-vibration technology into the camera has the advantage of making
the feature available to any lens attached to a supported camera, but it has the disadvantage of not being tailored to each focal length range.
What is distance data and which lenses support it?
Many Canon EF lenses have the ability to send distance data to the camera. For example, if you’re currently focussed on an object 4 metres from the camera then the
lens would send that approximate distance data to the camera body.
Canon have built and sold lenses since 1990 with this data, but it wasn’t until 2004, with the advent of E-TTL II flash metering, that Canon really put it to good use.
E-TTL II has the ability to factor distance data into flash metering calculations under certain conditions. This distance data can improve the reliability of flash
metering when it’s available and appropriate.
For more information on this topic please consult my EOS flash photography article, which has a section on E-TTL II and a list of Canon EF lenses capable of
returning distance data.
What is a lens element?
There’s some confusion of terminology here. The word “lens” refers both to a single chunk of shaped glass (think of the single lens of a magnifying glass) and the
tube-shaped device containing such lenses which you fasten to the end of your camera.
A lens element is a single piece of shaped glass or crystal. Camera lenses these days contain anywhere from 4 lens elements and up. They are frequently arranged in
optical groups within the barrel. For that reason you may hear of a given lens having, say, 18 elements in 15 groups.
There are complex tradeoffs made in lens designs, so the number of elements and groups isn’t always the most reliable indicator of image quality. Simpler lenses with
just a few elements tend to offer good results because they are so simple. Flare in particular (light reflection between elements in this case) is vastly reduced.
However, wide angle and telephoto lens designs generally require more elements to correct for various optical aberrations.
What is a lens coating?
As anyone who has looked through a window knows, glass both reflects light and lets light pass through. And reflections can easily happen at oblique angles as well as
when you look at a lens straight-on. Camera lenses suffer from the same basic problem of reflections as windows. And excessive reflections within the lens can result
in lens flare - either a generalized loss of contrast or bright reflected blobs appearing in the picture.
The invention of lens coatings by German lensmaker Carl Zeiss in the mid 1930s revolutionized lens design. Such coatings are fine layers of transparent material
which are applied to the surface of lens glass and which minimize internal reflections within the lens. All modern camera lenses, including Canon EF lenses, are
multicoated to reduce reflections. Canon refer to their technology as SSC, or Super Spectral Coating.
You can easily tell a coated glass surface from an uncoated one. An uncoated piece of glass reflects a lot of light, and reflected white light is also white. A coated piece
of glass, however, reflects far less light and the light that is reflected is often greenish, purplish or reddish. These apparent colours, it should be noted, are artefacts of
the way coatings absorb reflections, and do not mean that photos taken through decent quality coated glass are going to be tinted one colour or another.
Lens coatings have two drawbacks. First, they must be kept scrupulously clean at all times, as oils and dirt interfere with the way they work. Fingerprints are
extremely obvious on coated glass. Second, many lens coatings are fairly fragile and are easily scratched, so care is required in handling and cleaning them. Some
lens and filters include hardened surfaces over the top of the coatings to protect them, but this is not universal.
What do “aspheric” or “aspherical” mean?
The glass elements which make up a traditional camera lens can be thought of as cross-sections of a large sphere. That is to say that the curvature of each surface is
even. The problem with spherical lens designs is that light passing through the outer edges of curved camera lenses focus at different points from light passing
through the centre. This causes focus errors, or spherical aberration and other forms of optical problems. Spherical lenses work fine if the recording surface is also
spherical (eg: the human eyeball), but in the case of cameras it’s not - the film surface or image chip surface is always flat.
One way to fix the problem is to add additional lens elements to correct for the aberration. A generally more efficient way to fix it is to make a lens element which is
not a sphere in cross section. In other words the curvature of the lens varies from the middle to the edges. Such an aspherical lens element can help simplify lens
design by minimizing the number of elements required and can result in a sharper image. Aspherical elements are particularly useful for correcting distortion in
wide-angle lenses.
There are three basic ways to make an aspherical element. The expensive way is to grind a piece of glass down to the right shape. This is quite difficult owing to the
extreme precision required to achieve the complex geometry, and so only some L series lenses use ground aspherical elements in Canon’s lens lineup. Another way is
to mould a glass lens element. Such glass moulded aspherical lens elements are used in a number of Canon’s less expensive lenses. The cheapest way is to cement a
plastic resin aspheric surface to the top of a glass spherical element. Such lenses are known as replicated aspherical elements and are particularly common among
point and shoot cameras.
Note that some lensmakers, particularly Sigma, use the terms “aspherical” or “ASPH” as marketing labels. However many modern lenses made by other makers
such as Canon also employ aspherical elements - they simply don’t advertise this fact on the outside of the lens. It’s important to remember that lenses with
aspherical elements are not automatically and intrinsically better than lenses without. Sometimes they are, though this is usually for a variety of other factors, not
merely the fact that they use aspherical elements.
What is low dispersion glass?
Low dispersion glass and its variants - ultra-low dispersion (UD) glass, extra-low dispersion (ED) glass - is expensive optical glass which can reduce unwanted colour
fringing and other optical problems in lenses, particularly long telephoto lenses.
Dispersion is the rainbow effect seen with prisms and the like - white light being split up into a rainbow spectrum of its constituent wavelengths. Low dispersion glass
does not disperse white light as much as regular glass, thereby reducing the amount of correction required to compensate for the phenomenon.
What is fluorite?
Technically, calcium fluorite isn’t glass. It’s actually a type of crystal produced synthetically by Canon and used in many of their top of the line L series lenses in
place of low dispersion glass. It’s an expensive material but is extremely useful for minimizing optical lens aberrations, particularly with telephoto lenses.
What are diffractive optics (DO)?
DO lenses contain a new type of lens element unique to Canon’s product lineup. Such lens elements, multi-layer diffractive elements, are nearly flat lens elements
with extremely fine grooves etched into them. They exploit the principles of optical diffraction rather than optical refraction.
The advantage of such DO elements is that they do a very good job of reducing chromatic aberration (colour fringing), a particularly significant problem in long
telephoto lenses. They can also be made much lighter than regular low-dispersion or fluorite lens elements, thereby shortening the length and reducing the weight of a
large telephoto lens considerably.
Unfortunately, lenses with DO elements are at present quite expensive, and have some issues with lens flare under some lighting conditions. Canon DO lenses, while
professional products, are not sold as L lenses and are marked by a pale green stripe around the end of the lens rather than a red one.
What is rear or internal focussing?
Many lenses become physically longer or shorter when you adjust focus. In other words they have two nested tubes which telescope in and out as you rotate the focus
ring. This design, while inexpensive to make, is generally undesirable because when a lens extends or contracts there will always be air and dust sucked inside it. And
inevitably this yields a bit of dust buildup over years of use.
Many Canon lenses use rear focusing (RF) or internal focussing (IF) instead. In rear focussing the lens elements closest to the camera move back and forth when you
focus but the frontmost elements do not. In internal focussing some glass elements inside the lens move within the lens barrel. In both cases the lens does not change
length at all because all lens element motion is contained within the lens barrel.
Another advantage of rear and internal focussing is that the end of the lens does not rotate during focussing. Many lenses which extend when you focus also rotate,
which can be a nuisance if you use polarizing filters or graduated neutral density filters
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