Essentials: The Lowdown On Lenses
Glenn Randall

When you invest in an slr camera, you're paying for flexibility, which in broad terms means the ability to swap lenses. Options are great, but for your first lens, buy the fastest midrange zoom you can afford. Unless you plan to exclusively shoot wildlife, landscapes, or close-ups, try a 35-70mm or 28-80mm. A midrange zoom will cover a budding photographer's needs in one convenient package, and it saves weight, bulk, and money compared to a flock of fixed-focal-length lenses. It also saves time better spent shooting than changing lenses.

Not all zooms are created equal, however. Better zooms are sharper, and they cause less distortion. Less expensive zooms are "slow"--that is, they have smaller maximum apertures (f/4 to f/5.6, versus f/2.8 on more expensive zooms), forcing you to use slower shutter speeds. And slow shutter speeds, in turn, can lead to fuzzy photos.

Of course, fast zooms are dramatically heavier and bulkier, because the front lens--the actual hunk of glass--must be considerably larger to gather more light. They're also much more costly, since glass ground fine enough for photography is simply expensive. For example, Nikon's 35-80mm f/4-f/5.6 lens weighs nine ounces and costs $155. Add an f-stop, and you can get Nikon's 35-70mm f/2.8 zoom: It weighs nearly three times as much and costs $980.

Do you need a fast zoom? A slow maximum aperture of f/4 or f/5.6 can spell trouble if you're trying to stop action in low light using fine-grain slide film. Slower zooms are certainly adequate, however, if you're photographing stationary subjects from a tripod, or using a flash, or mostly shooting faster (400 to 1,000 ISO) print film. For the best image quality, think about zooms with a 1:2 or 1:3 range from shortest to longest focal length. Lenses with extreme ranges (such as 28-200mm) don't render photos as sharp as midrange zooms.

Photographers interested strictly in either landscapes or close-ups may find zooms to have a few disadvantages over fixed focal-length lenses. First, zooms lack depth-of-field scales, important for judging landscape shots. Second, most "macro" zooms won't focus as close or produce as sharp an image as a true, fixed-focal-length macro lens.

If photographing wildlife is your passion, you might first consider a telephoto lens, reaching out to 300mm, so you can stay far enough away to capture skittish creatures. Since most wild animals are active early and late in the day, it's best to use a fast lens, which will stop action in low light. By virtue of size, any telephoto will cost you more than an average midrange zoom, but a starting point might be $650 for a 100-300mm f/4.5-f/5.6 lens. Of course, you can spend as outlandishly as you like.