Magnification is a function of the subject's size, its distance from the camera and the focal length of the lens used to make the photo. Using a longer lens, moving closer to the subject or choosing a larger subject will make the subject appear larger in the image frame.
Many wildlife photographers who use DSLRs and long lenses prefer "cropped-sensor" cameras to full-frame ones because the smaller sensors crop in on the image formed by the lens, producing a tighter framing than the same lens would produce on a camera with a larger sensor. For practical purposes, this is "magnification," although technically, it's not: A given focal length focused at a given distance produces a given magnification at the image plane. If you put a 300mm lens on a full-frame camera and focus on a moose at a certain distance, the moose's image will be 0.5 inches high at the image plane. Since a full-frame sensor measures approximately 1x1.5 inches, the moose's image will take up half the height of the frame. If you then put the same lens on an APS-C (1.5x) DSLR and take a photo with that camera from the same spot, the moose's image will still be 0.5 inches high at the image plane, but the APS-C sensor measures approximately 0.6x0.9 inches, so that the 0.5-inch-high moose image will occupy nearly the entire height of the photo. For practical purposes, putting the 300mm lens on the APS-C camera effectively turns it into a 450mm, but really it doesn't—the APS-C sensor just crops the image produced by the lens at the image plane more tightly.
|Nikon AF-S 600mm ƒ/4G ED VR; Sony 300mm ƒ/2.8 G.|
It's commonly believed that long lenses compress perspective and short ones expand it. Actually, it's the shooting distance that determines the perspective; the focal length just determines the framing. You can prove this to yourself by putting your camera on a tripod, shooting an image with a long lens, then removing that lens, attaching a short one and shooting another shot from the same spot. Blow up the short lens shot so it covers the same field of view as the long lens shot, and you'll see that the perspective is the same. (Perspective refers to the spatial relationships among portions of a scene: how large one object appears relative to more distant or closer ones and how far apart the objects appear to be.)
We think of "telephoto compression" because we generally use long lenses at great distance—and shooting at great distance does indeed flatten perspective. And we think of "wide-angle expansion" because we generally use short lenses at close shooting distances—and shooting at close range does indeed expand perspective. From a landscape standpoint, choose your shooting distance (when possible) to produce the desired perspective and the focal length to frame the image as desired from that distance. Of course, in landscape (and wildlife) work, shooting from a desired distance isn't always possible, so you choose a focal length to frame, as desired, and live with the resulting perspective.
Depth Of Field
Long lenses produce less depth of field than shorter ones. This makes them great for shallow-depth-of-field selective-focus shots, but requires stopping them down when more depth of field is needed. But even stopping all the way down may not produce the desired depth of field, and stopping down increases the adverse effects of diffraction, reducing overall image sharpness. Due to the limited depth of field, when working with a long lens (especially a fast one wide open), precise focusing is imperative. (Tip: For wildlife subjects, focus on the near eye.) You'll have to work with your long lens for a while to get a "feel" for its depth-of-field characteristics.
Mirror lenses literally use mirrors to "fold" great focal length into a compact package. Besides much shorter physical length than conventional telephotos of equivalent focal length, advantages of mirror lenses include closer minimum focusing distances for a given focal length and cost. The drawbacks are less sharpness than conventional telephoto lenses, manual focusing only, often a single fixed aperture, and "doughnut"-shaped out-of-focus highlights. While none of the camera companies offers mirror lenses anymore, a number are available in mounts to fit most popular SLRs and DSLRs, such as Adorama's Pro-Optic 500mm ƒ/6.3 ($159 estimated street price) and 800mm ƒ/8 ($179). When you consider that major-brand 500mm telephoto lenses start at around $5,000, you can see why some photographers like to do it with mirrors.
|Canon EF 28-300mm ƒ/3.5-5.6L IS USM; Sigma 300mm ƒ/2.8 EX APO DG HSM; Tamron 200-500mm F/5-6.3 Di LD|
Long lenses magnify camera shake along with the image, so they're best used atop a sturdy tripod. For landscapes and other nonmoving subjects, a ball-type tripod head is ideal because it allows you to easily position the camera as desired, then lock it there with the twist of a knob. Bird-in-flight specialists generally prefer gimbal heads, which allow you to track moving subjects while providing good support. For some photographers, a rifle-stock support such as the BushHawk is comfortable and fast to use. Besides eliminating camera shake as a source of image blur, a tripod can lock your composition in so you can study it carefully. Focus using the zoomed live-view image and you won't accidentally alter the framing as you squeeze off the shot. A monopod is easier to carry around than a tripod and still provides much more support than handholding a long lens.
Note that since most long lenses are heavier than most camera bodies, you generally attach the lens rather than the camera body to the tripod head. Heavier long lenses come with tripod-mounting rings for this purpose.
What Do You Get For Your Money?
You can pay as little as $1,400 for a new top-brand 400mm lens or as much as $11,499 (same manufacturer, incidentally). What's the difference?
All-Around Performance. The higher-end lenses deliver better image quality, assuming proper shooting techniques are used because they employ better optical elements and more precise production tolerances. Higher-end lenses also provide better autofocus performance, faster maximum apertures and more rugged construction, with better weather, dust and temperature resistance.
Special Elements. Aspherical elements are generally used to minimize the distortion and spherical aberration (focusing of light rays coming through the edges of the lens closer to the lens than light rays coming through the center) that plague wide-angle lens designs—especially fast wide-angle lenses—but you'll also find them in some wide-to-telezooms to handle these problems and keep overall lens size down. One aspherical element can do the job of two or more "regular" elements. Aspherical elements aren't needed in prime long lenses.
Multicoatings. An ideal lens element would transmit all the light that strikes it. But in reality, each element reflects a portion of the light that strikes it, and so transmission is reduced. Each glass-to-air surface in a lens does this; in a zoom lens, which might have 20 or more such surfaces, the light loss can be extreme. So better lenses employ multiple coatings on each element surface to minimize reflections and increase transmittance. Multicoatings also help provide good color characteristics, and reduce ghosting and flare. Some lenses also employ fluorine coatings, which minimize problems with dust and water, and make the front element easier to clean.
|Canon EF 300mm ƒ/2.8L IS USM||17/13||1FL2UD||8.2 ft.||0.13X||52mm**||5.0x9.9||5.6 lbs.||$4,879||C|
|Canon EF 300mm ƒ/2.8L IS II USM||16/12||2FL.||6.6 ft.||0.18X||52mm**||5.0x9.8||5.2 lbs.||$7,299||C|
|Canon EF 300mm ƒ/4L IS USM||15/11||2UD||4.9 ft||0.24X||77mm||3.5x8.7||2.6 lbs.||$1,449||C|
|Canon EF 400mm ƒ/2.8L IS USM||17/13||1FL2UD||9.8 ft.||0.15X||52mm**||6.4x13.7||11.8 lbs.||$7,999||C|
|Canon EF 400mm ƒ/2.8L IS II USM||16/12||2FL||8.9 ft.||0.17X||52mm**||6.4x13.||6.4x13.||$11,499||C|
|Canon EF 400mm ƒ/4 DO IS USM||17/13||1DO1FL||11.5 ft.||0.12X||52mm**||5.0x9.4||4.3 lbs.||$6,469||C|
|Canon EF 400mm ƒ/5.6L USM||7/6||1SUD1UD||11.5 ft.||0.12X||77mm||3.5x10.1||2.8 lbs.||$1,339||C|
|Canon EF 500mm ƒ/4 IS USM||17/13||1FL2UD||14.8 ft.||0.12X||52mm**||5.8x15.2||8.5 lbs.||$6,999||C|
|Canon EF 500mm ƒ/4L IS II USM||16/12||2FL||12.1 ft.||N/S||52mm**||5.7x15.1||7.0 lbs.||$10,499||C|
|Canon EF 600mm ƒ/4L IS USM||17/13||1FL2UD||18.0 ft.||0.12X||52mm**||6.6x18.0||11.8 lbs.||$9,199||C|
|Canon EF 600mm ƒ/4L IS II USM||16/12||1FL||14.8 ft.||N/S||52mm**||6.6x17.6||8.6 lbs.||$12,999||C|
|Canon EF 800mm ƒ/5.6L IS USM||18/14||2FL1UD1SUD||19.7 ft.||0.14X||52mm**||6.4x18.1||9.9 lbs.||$13,999||C|
|Nikon AF-S 300mm ƒ/2.8G VR II||11/8||3ED||7.2 ft.||0.16X||52mm**||4.9x10.5||6.4 lbs.||$5,899||N|
|Nikon AF-S 300mm ƒ/4D IF-ED||10/6||2ED||4.8 ft.||0.27X||77mm||3.5x8.8||2.9 lbs.||$1,494||N|
|Nikon AF-S 400mm ƒ/2.8G ED VR||14/11||3ED||9.2 ft.||0.16X||52mm**||6.3x14.5||10.2 lbs.||$9,549||N|
|Nikon AF-S 500mm ƒ/4G ED VR||14/11||3ED||12.6 ft.||0.15X||52mm**||5.5x15.4||8.6 lbs.||$8,579||N|
|Nikon AF-S 600mm ƒ/4G ED VR||15/12||3ED||15.7 ft.||0.14X||52mm**||6.5x17.5||11.2 lbs.||$10,299||N|
|Sigma 300mm ƒ/2.8 EX APO DG HSM||11/9||2ELD||8.2 ft.||0.13X||346mm**||4.7x8.4||5.3 lbs.||$3,399||CNPSiSo|
|Sigma 500mm ƒ/4.5 EX DG APO HSM||11/8||2ELD||13.1 ft.||0.13X||46mm**||4.8x13.8||6.9 lbs.||$4,999||CNPSiSo|
|Sigma 800mm ƒ/5.6 EX APO DG HSM||12/9||2ELD||3.0 ft.||0.11X||46mm**||6.2x20.5||10.5 lbs.||$6,599||CNSi|
|Sony 300mm ƒ/2.8 G||13/12||3ED||6.6 ft.||0.18X||42mm**||4.8x9.5||5.1 lbs.||$6,999||So|
|Sony 500mm ƒ/4 G||11/10||3ED||13.1 ft.||0.14X||42mm**||5.5x14.6||7.6 lbs.||$12,999||So|
|Canon EF 28-300mm ƒ/3.5-5.6L IS USM||23/16||3UD3ASPH||2.3 ft.||0.30X||72mm||3.6x7.2||3.7 lbs.||$2,689||C|
|Canon EF 75-300mm ƒ/4-5.6 III 13/9||13/9||None||4.9 ft.||0.25X||58mm||2.8x4.8||16.9 oz.||$199||C|
|Canon EF 75-300mm ƒ/4-5.6 III USM||13/9||None||4.9 ft.||0.25X||58mm||2.8x4.8||16.9 oz.||$234||C|
|Canon EF 70-300mm ƒ/4-5.6 IS USM||15/10||1DO1ASPH||4.9 ft.||0.26X||58mm||3.0x5.6||22.2 oz.||$649||C|
|Canon EF 70-300mm ƒ/4.5-5.6 DO IS USM||18/12||2UD||3.9 ft.||0.19X||58mm||3.2x3.9||25.4 oz.||$1,399||C|
|Canon EF 70-300mm ƒ/4-5.6L IS USM||19/14||1FL1SUD||4.9 ft.||0.21X||67mm||3.5x5.6||2.3 lbs.||1,$599||C|
|Canon EF 100-300mm ƒ/4.5-5.6 USM||13/10||None||5.9 ft.||0.20X||58mm||2.9x4.8||19.0 oz.||$470||C|
|Canon EF 100-400mm ƒ/4.5-5.6L IS USM||17/14||2ED||19.3 in.||0.20X||72mm||3.6x7.4||3.0 lbs.||$1,699||C|
|Nikon AF-S 28-300mm ƒ/3.5-5.6G ED VR||19/14||3ED||4.9 ft.||0.32X||72mm||3.3x4.5||28.2 oz.||$1,049||N|
|Nikon AF 70-300mm ƒ/4-5.6G||13/9||3ED||4.9 ft.||0.26X||62mm||2.9x4.6||15.0 oz.||$172||N|
|Nikon AF-S VR 70-300mm ƒ/4.5-5.6G IF-ED||17/12||4SDL||7.5ft.||0.25X||67mm||3.1x5.6||26.3 oz..||$589||N|
|Nikon AF VR 80-400mm ƒ/4.5-5.6D ED||17/11||1SDL||6.4 ft||0.21X||52mm||3.6x6.7||2.7 lbs.||$1,849||N|
|Nikon AF-S 200-400mm ƒ/4G ED VR II||24/17||3SDL||19.7 in.||0.28X||72mm||4.9x14.4||7.4 lbs.||$6,999||N|
|Sigma 50-500mm ƒ/4.5-6.3 APO DG OS HSM||20/6||1SDL||4.0 ft.||0.32X||95mm||4.1x8.6||4.3 lbs.||$1,659||CNPSiSo|
|Sigma 70-300mm ƒ/4-5.6 DG Macro||14/10||2FLD1SLD||4.9 ft.||0.25X||58mm||3.0x4.7||18.7 oz.||$169||CNPSiSo|
|Sigma 70-300mm ƒ/4-5.6 APO DG Macro||14/10||3SDL||4.9 ft.||0.25X||58mm||3.0x4.7||18.7 oz.||$239||CNPSiSo|
|Sigma 70-300mm ƒ/4-5.6 DG OS 16/11||16/11||3SDL||4.9 ft.||0.26X||62mm||3.0x5.0||21.5 oz.||$359||CNPSiSo|
|Sigma 120-300mm ƒ/2.8 EX DG OS APO HSM||23/18||2ELD1SLD||4.9 ft.||0.12X||105mm||4.5x11.4||6.5 lbs.||6.5 lbs.||CNSi|
|Sigma 120-400mm ƒ/4.5-5.6 DG APO OS HSM||21/15||2SDL||7.2 ft.||0.24X||77mm||3.6x8.0||3.9 lbs.||$999||CNPSiSo|
|Sigma 150-500mm ƒ/5-6.3 APO DG OS HSM||21/15||2ED||6.6 ft.||0.19X||86mm||3.7x9.9||4.2 lbs.||$1,059||CNPSiSo|
|Sigma 200-500mm ƒ/2.8 APO EX DG 17/13||17/13||None||19.7 in.||0.13X||72mm**||9.3x28.6||34.6 lbs.||$25,999||CNSi|
|Sigma 300-800mm ƒ/5.6 EX DG APO HSM||18/16||2ELD||3.9 ft||0.14X||46mm**||6.2x21.3||12.9 lbs.||$7,999||CNSi|
|Sony 70-300mm ƒ/4.5-5.6 G||16/11||2ED||4.9 ft||0.25X||62mm||.3x5.4||28.2 oz.||$999||So|
|Sony 75-300mm ƒ/4.5-5.6||13/10||None||5.0 ft.||0.25X||55mm||2.8x4.8||16.2 oz.||$249||So|
|Sony 70-400mm ƒ/4-5.6 G||18/12||2ED||19.3 in.||0.27X||77mm||3.8x7.8||.3 lbs.||$1,999||So|
|Tamron 28-300mm F/3.5-6.3 XR Di LD Asph.||12/9||1XR1LD3ASPH||19.3 in.||0.34X||62mm||2.9x3.3||14.8 oz.||$419||CPNSo|
|Tamron 28-300mm F/3.5-6.3 XR Di VC LD Asph.||18/13||1XR2LD3ASPH||4.9 ft.||0.33X||67mm||3.1x3.9||19.4 oz.||$629||CN|
|Tamron 70-300mm F/4-5.6 Di LD||13/9||1LD||5.0 ft.||0.50X||62mm||3.0x4.6||15.3 oz.||$199||CPNSo|
|Tamron SP 70-300mm F/4-5.6 Di VC USD||17/12||1XLD1LD||4.9 ft.||0.25X||62mm||3.2x5.6||27.0 oz.||$499||CNSo|
|Tamron SP 200-500mm F/5-6.3 Di LD||13/10||2LD||8.2 ft.||0.20X||86mm||3.7x8.9||2.7 lbs.||$949||CNSo|
|Tokina AF 80-400mm ƒ/4.5-5.6 AT-X D||16/10||1SLD||8.2 ft.||0.19X||72mm||3.1x5.4||2.2 lbs.||$589||CN|
|FOR APS-C ONLY|
|Canon EF-S 55-250mm ƒ/4-5.6 IS II||12/10||1UD||3.6 ft.||0.31X||58mm||2.8x4.3||13.8 oz.||$299||C|
|Sigma 18-250mm ƒ/3.5-6.3 DC OS HSM||18/14||4SLD3ASPH||17.7 in.||0.29X||72mm||3.1x4.0||22.2 oz.||$479||CNPSiSo|
|Nikon AF-S DX 55-300mm ƒ/4.5-5.6G ED VR||17/11||2ED1HR||4.6 ft.||0.28X||58mm||3.0x4.8||18.7 oz.||$399||N|
|Pentax DA* 300mm ƒ/4 SDM||8/6||ED||4.7 ft.||0.24X||77mm||3.3x7.4||2.4 lbs.||$1,399||P|
|Sony DT 18-250mm ƒ/3.5-6.3||16/13||3ASPH||19.2 in.||0.29X||62mm||3.0x3.4||15.5 oz.||$599||So|
|Tamron AF18-270mm F/3.5-6.3 Di II VC PZD||16/13||2LD3ASPH||19.3 in.||0.26X||62mm||2.9x3.5||15.9 oz.||$6,495||CNSo|
|FOR FOUR THIRDS SYSTEM:|
|Olympus Zuiko Digital ED 300mm ƒ/2.8||13/11||3ED||7.9 ft.||0.15X||43mm||5.0x11.2||7.2 lbs.||$6,999||4/3|
|Olympus Zuiko Digital ED 50-200mm ƒ/2.8-3.5 SWD||16/15||3ED||3.9 ft.||0.21X||67mm||3.4x6.2||2.2 lbs.||$1,199||4/3|
|Olympus Zuiko Digital ED 70-300mm ƒ/4.0-5.6||14/10||3ED||3.1 ft.||0.50X||58mm||3.1x5.0||21.8 oz.||$399||4/3|
|Olympus Zuiko Digital ED 90-250mm ƒ/2.8||17/12||3ED||8.1 ft.||0.08X||105mm||4.9x10.9||7.2 lbs.||$5,999||4/3|
|FOR MICRO FOUR THIRDS SYSTEM:|
|Olympus M.Zuiko Digital ED 75-300mm ƒ/4.8-6.7||18/13||1SED2ED3HR||3.1 ft.||0.18X||58mm||2.8x4.6||15.2 oz.||$899||m4/3|
|Panasonic Lumix G Vario 100-300mm ƒ/4.0-5.6||17/12||1ED||4.9 ft,||0.21X||67mm||2.9x5.0||18.3 oz.||$499||m4/3|
* Type and (when available) number of special elements used in lens; see text for descriptions
**Indicates drop-in rear filter; no asterisk indicates front screw-on filter size
*** Mounts in which lens is available: C = Canon EF, N = Nikon F, P = Pentax K, Si = Sigma SD, So = Sony A, 4/3 = Four Thirds System, m4/3 = Micro Four Thirds
Max. Magnif: Maximum magnification—1.0X equals life-size, 0.25X equals ¼ life-size (at the image plane)
N/S = not stated by manufacturer
|Zoom lenses provide a whole range of focal lengths in a single package and are very popular for that reason. But they also offer a great way to acquire long focal lengths on the cheap: While the lowest-priced 300mm fixed-focal-length lenses cost around $1,400, you can pick up a good 70-300mm zoom from the same camera maker for less than half that (avoid the really low-priced telezooms). You're going to lose a stop of lens speed, and some AF and optical performance, but the $400-$700 70-300s are good performers and great choices for the budget-limited wildlife shooter. Zooms prove an even better deal at longer focal lengths: While fixed-focal-length 500mm superteles start at around $5,000, Sigma and Tamron offer 150-500mm and 200-500mm zooms, respectively, for about one-fifth that price. Again, you'll give up some lens speed and AF and optical performance, but you'll still get very capable lenses—and focal lengths you otherwise couldn't enjoy.|
The 70-200mm Zooms
|Many outdoor photographers love the 70-200mm zooms (available in fast ƒ/2.8 and—from Canon for EOS DSLRs—ƒ/4 varieties), both for landscapes and for wildlife subjects they can approach fairly closely. We didn't include them here because they aren't really supertelephotos (although you can add a 2.0x teleconverter to a 70-200mm ƒ/2.8 and get a versatile 140-400mm ƒ/5.6).|
|Teleconverters are small tubes that fit between the camera body and a telephoto lens. They contain one or more elements and increase the focal length of the lens to which they're attached by 1.4x, 1.7x, 2.0x and even 3.0x. Advantages include cost (a $100-$500 converter is a lot cheaper than a supertele lens), compact size and no change in minimum focusing distance: Attach a 2.0x converter to a 300mm ƒ/4 lens that focuses down to 4.9 feet, and you get a 600mm ƒ/8 lens that focuses down to 4.9 feet. The drawbacks are a slight loss of image quality, slowed (or nonexistent) AF performance and (as hinted in the preceding sentence) a loss of light: one stop for a 1.4x, 1.5 stops for a 1.7x and two full stops for a 2.0x. Most DSLRs require ƒ/5.6 for autofocusing to work, so adding a converter to a slower lens, like a 70-300mm ƒ/4-5.6 zoom, means having to focus manually—and ƒ/8 with a 1.4x converter and ƒ/11 with a 2.0x provide a very dark viewfinder image for manual focusing. That aside, a 300mm ƒ/4 lens and 1.4x converter give you a 420mm ƒ/5.6 lens that focuses down to around five feet, great for everything from birds in flight to flowers and butterflies (the only major-brand 400mm ƒ/5.6 fixed-focal-length lens has a minimum focusing distance of 11.5 feet).|