Black and White Photography

effect; for instance, the slight flattening effect of a short telephoto lens

(85–105mm) often flatters portrait subjects.

Some telephoto lenses are large and bulky and therefore difficult to hold

steadily by hand. Since camera or lens movement during exposure may cause

blur in the resulting image, take extra care to steady the camera when using

larger telephoto lenses. There are many ways to do this, but using a tripod is

the most common method. Using a fast shutter speed also can reduce the

chances of camera movement during exposure.

Zoom lens. Zoom lenses, unlike fixed-focal-length lenses, offer a range of focal

lengths, from wide-angle to telephoto (35–80mm, 28–200mm, 35–300mm,

and so forth). Many new cameras come equipped with a moderate wide-angleto-

telephoto zoom, such as 35–80mm. Zoom lenses also come in a range limited

to wide-angle or, more commonly, telephoto focal lengths. Available wideangle

zoom lenses have ranges such as 17–35mm, 20–35mm, and 20–40mm;

telephoto zoom lenses include such ranges as 70–200mm and 100–300mm.

Zoom lenses can be set at any focal length within their range. So in theory

you can use a 35–80mm lens at 38mm, 46mm, or 76mm, lengths that are not

available at all in fixed-focal-length lenses. You may not know the exact focal

length you’ve set, because the scale on your zoom lens, if there is one at all,

can’t be set that precisely. But this focal-length flexibility does allow you to compose a subject more critically without physically moving; you can loosen

the composition by zooming back a bit to reduce the size of the subject (fitting

in more of the overall scene) or tighten it by zooming closer to magnify the

subject.

The biggest advantage of zoom lenses, however, is their convenience. You

only need one or two lenses, say, a wide-angle zoom and a telephoto zoom, to

cover a very wide range of focal lengths. This means less bulk and weight in

your camera bag and less changing of lenses when photographing. This can be

critical when photographing spontaneously or shooting quick-changing subjects,

situations when you may otherwise lose the moment if you have to take

the time to remove one lens and replace it with another.

The quality difference between fixed-focal-length lenses and zooms is a subject

of some debate. Modern zoom lenses are optically excellent, though many

older models are not. Zoom lenses typically may have more bulk and weight

than your fixed-focal-length lenses. They also are often more expensive.

Possibly the biggest disadvantage of zoom lenses is that they are almost

always relatively slow; they have smaller maximum apertures, which means

they are not as useful when you are photographing in low-light situations without

flash or other accessory lighting. Almost any 50mm fixed-focal-length normal

lens, for example, will allow much more light in to the film when set at its

maximum aperture than would a 35–80mm zoom set at 50mm. For example,

a fixed-focal-length 50mm lens may have a maximum aperture of f/2, while an

35–80mm lens set at 50mm may have a maximum aperture of only f/4.