Wide-Angle Lenses

Wide-angle lenses are good for full-length fashion shots, as they can emphasize the garment. Photo by Lynne Eodice

Wide-angle lenses take in a wider angle of view than "normal" lenses, and have shorter focal lengths. For 35mm cameras, wide-angle lenses run from 35mm (which provides a 63° angle of view, compared to 46° for a 50mm "normal" lens) down to 14mm (114° angle of view), with those under 21mm considered "superwides."

Probably the most practical use for wide-angle lenses is to get everything in when you can't move far enough away to do it with a longer lens. Another common use is to exaggerate the size of a nearby subject by moving in very close to it, while the lens's wide angle of view keeps background subjects in the picture. Fashion photographers use wide-angles for low-angle full-figure shots that really show off long dresses.

It's commonly believed that wide-angle lenses "distort" perspective. Actually, focal length doesn't change perspective. Perspective is an effect of camera location—how far the camera is from the subject. Folks generally move a lot closer when using wide-angle lenses, and it is the close shooting distance that "expands" the perspective—not the short focal length. So, if you want to expand perspective—make close objects appear much larger than more distant ones, and seemingly increase the distance between them—move in close with a wide-angle lens. You'd get the same expansion with a longer lens, but its narrower angle of view wouldn't include anything but the immediate subject, so you won't notice the effect. Conversely, if you crop in on the center of a shot made with a wide-angle lens, you'll get a "telephoto compression" effect—only the most distant portion of the scene will be included in the picture, just as if you'd shot from the same spot with a longer lens.

Long lenses magnify the subject, bringing distant subjects to you when you can't get to them.

Long Lenses

Lfarther away ong lenses are those longer than "normal" lenses—those longer than 50mm for a 35mm camera. Popular ones include 85mm, 100mm, 135mm, 200mm, 300mm and 400mm (and, among wildlife pros, 600mm). They top out around 1200mm (really long lenses are really expensive).

The most obvious use for long lenses is to bring distance subjects to you when you can't get to them. Wildlife and sports photographers use long lenses to get those dramatic close-ups. But short telephotos (85-135mm for 35mm cameras) are ideal portrait lenses, because they produce a good head size at a shooting distance that provides pleasing perspective. (If you use as shorter lens, you have to move closer to get a good head size, and this expands perspective, resulting in pointy noses and a "warped" look, and if you use a longer lens, you have to move to get a good head size, and moving back compresses perspective, resulting in a "flattened" look.) Another good use for really long lenses is to zero in on a subject from a distance to compress the perspective—those "stacked-up" rush-hour freeway traffic photos are made this way.

Short telephoto lenses (85-135mm for a 35mm camera) are ideal for portraits, as they produce a good head size at a shooting distance that produces pleasing perspective. Photo by Lynne Eodice

Long lenses are commonly referred to as "telephotos," but not all long lenses are telephotos. Telephotos utilize a particular optical design in which the lens's physical length is shorter than its focal length: the optical center is actually in front of the lens.

Because they magnify camera movement as well as the subject, long lenses are best used on tripods. In fact, longer lenses generally come with built-in tripod mounts: because they're heavier than most camera bodies, you actually attach the lens itself to the tripod. The rule of thumb is to put the camera on a tripod if you can't use a shutter speed at least equal to the reciprocal of the lens' focal length (i.e., at least 1/200 with a 200mm lens), but in practice it's wise to put any lens of 300mm or longer on a tripod whenever possible regardless of shutter speed. Canon and Nikon offer telephotos with built-in image stabilizers that let you get sharper shots hand-held, and these devices really do work, but it's still best to use a tripod with really long lenses (switch off the image stabilizer when the lens is on a tripod).

Depth of field is limited with long lenses, a fact that portrait photographers can use: Shoot with the lens wide open, and you can throw a distracting background totally out of focus, so that it is not longer a distraction.

Telephoto "compression" occurs because long lenses fill the frame with a distant subject. If you switched to a wide-angle lens, then cropped the resulting image to cover only the area in the telephoto shot, the perspective would be the same (although the greatly enlarged wide-angle segment would be far grainier).

A special type of long lens is the mirror lens, also known as the reflex lens. Mirror lenses provide long focal lengths in short, lightweight packages by "folding" the light back and forth inside the lens barrel. Mirror lenses are much shorter than conventional refracting lenses of equal focal length, have much closer minimum focusing distances, and are generally not quite as sharp as their refracting counterparts. Most mirror lenses lack a diaphragm (f-stops), so exposure is controlled by adjusting the shutter speed (or by using neutral-density filters, which are built into many mirror lenses). Many mirror lenses also focus past infinity, to compensate for the physical expansion and contraction of the lens that can occur when using them in hot or cold situations. Early mirror lenses were extremely fragile, and the type still requires gentler treatment than other lenses, actually. Most of today's mirror lenses are catadioptric, meaning they contain refracting lens elements as well as mirrors, to produce even more-compact lenses.

Zoom Lenses

Probably the most popular type of lens today is the zoom, which incorporates a whole range of focal lengths in a single lens. Operating the zoom ring alters the relationships among the elements in the lens, thus altering the focal length. Popular zoom lenses include the 35-80mm, 28-105mm, 70-210mm and 28-200mm, with many other focal length ranges available. At the focal-length extremes, Pentax offers a 17-28mm fisheye zoom, and Nikon once offered a 1200-1700mm supertele zoom. There are quite a few wide-angle zooms (17-35mm and 20-35mm being the most common), with Sigma's 15-30mm being the widest nonfisheye zoom.

A telephoto trick: If you want a big sun in your picture, focus on a nearby subject (at or close to the lens's minimum focusing distance), and the out-of-focus sun in the background will be huge. But never look at the sun through a long lens—eye damage will result. Instead, compose and focus with the sun just out of frame, then take your eye away from the finder, move the camera slightly to include the sun in the picture, and shoot.

Early zoom lenses weren't pinpoint sharp, but today's major-brand zooms by and large are excellent—even pros use zoom lenses nowadays. By nature, zooms are heavier than single-focal-length lenses, and slower (there are some f/2.8 zooms, but these cost considerably more, so most zooms have maximum apertures in the f/3.5-5.6 range). Many have variable maximum apertures: a 70-210mm f/4-5.6 has a maximum aperture of f/4 at the 70mm setting and a maximum aperture of f/5.6 at the 210mm setting. TTL metering automatically compensates for this, but when using a hand-held meter, you have to use the appropriate index mark (wide or tele) when setting the aperture.

Not all "zoom" lenses are true zooms. True zooms maintain focus as the focal length is changed, while vari-focal lenses change focus each time the focal length is changed. With AF cameras, this is not a problem, but when focusing manually, be sure to focus at the focal length you're going to use for the shot (it's generally easier to focus at the longest focal length, then zoom to the desired setting for the shot, but this doesn't work with vari-focal "zooms" that change focus when they are zoomed). Generally, the zooms with variable maximum apertures are vari-focal types.

Deliberately throwing bright highlights out of focus with a mirror lens produces this neat special effect.

In addition to the benefits of providing a whole range of focal lengths in a single lens, a zoom lens enables you to produce special effects by zooming during a long exposure, thus creating an "explosion" effect in the image..

Zoom lenses provide a whole range of focal lengths in a single, convenient package.

A zoom lens is handy when you can't easily move closer or farther away, as when doing aerial photography. Just operate the lens's zoom control to crop the scene as desired.

Mirror lenses aren't quite as sharp as the best refracting telephotos, but the major-brand ones get the job done. Not the tell-tale "doughnut"-shaped out-of-focus highlights in the background.

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By Mike Stensvold / copyright 1998-2002 by PRIMEDIA Specialty Group Inc.