“What’s the best lens for taking pictures?”
“All of them, but only one at a time.”
A camera lens converts and focuses a scene onto photosensitive surface (digital image sensor or film). The lens is the glass “window” we see at the front of the camera. It is round and convex and sometimes has rings around it for focusing and setting aperture; sometimes also the shutter speed.
| Wide-angle lenses distort unfavorably. Cows likely won’t care, but children and most self-respecting adults will insist that the photographer, “destroy all copies immediately!” |  |
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| Single Lens Reflex lenses Left to right: 24mm wide angle, 135mm telephoto, 50mm normal, 300mm telephoto |
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There is no perfect camera lens for every need. A wide-angle (short focal length) lens will “see” a wider angle of view and allow the photographer to record what is needed when confined by tight spaces. A telephoto (long focal length) lens will bring the subject closer, much the same as binoculars or a telescope. A telephoto us highly useful for taking pictures of distant wildlife when to move too closely the elk or bear might decide to flee.
A zoom lens, which covers a range of near and far, is a great tool for photographers who need versatility in a single lens.
But, each lens has its drawbacks. A wide-angle lens distorts the foreground and the background recedes unnaturally; vertical angles veer up and away. A telephoto lens is difficult to hold still enough by hand to prevent camera movement/blur. A tripod for stabilization is regularly required. The “longer” the lens the smaller the maximum aperture is.
Zoom lenses would seem to combine the best of both worlds: wide-angle, normal, telephoto, and they are the most popular and widely used lenses today. Most digital and some automatic film cameras come equipped with zoom lenses. They offer the most versatility to the majority of photographic hobbyists and average weekend shooters.
Examples of same scene with different focal lengths–
 24mm, wide angle |
 50mm, normal |
 135mm, short telephoto |
 300mm, long telephoto |
The following group of photos was taken from the same spot.
The camera was mounted to a tripod and lenses were changed to illustrate changes in focal length and aperture.
(Can you guess why the photos on the left have blurrier backgrounds and foregrounds than those on the right? We'll
discuss the answer in the how-to on aperture.)
 24mm, f/2.8 |
 24mm, f/22 |
 50mm, f/1.4 |
 50mm, f/16 |
 135mm, f/2 |
 135mm, f/22 |
 300mm, f/4.5 |
 300mm, f/22 |
Shoot a roll of film or fill up a digital card, practicing with different focal lengths. Try photographing people/a person, with a wide-angle zoom lens setting or wide-angle lens. Practice setting various apertures with different focal lengths to see what happens with depth of field. Don’t be hesitant to release the shutter. Consume film copiously just for play, to see “what happens.” For those of you who do not have a zoom lens or interchangeable lenses, practice moving closer to your subject–move closer than you’d ever do in “real life,” and see what happens.