Zoom properties of digital cameras and/or zoom lenses are convenience ways for enlarging or reducing an image without the need to get closer or farther away. You'll find zoom capabilities of digital cameras to be especially useful for sports and scenic photography or other situations where your movement is restricted.

Only the least expensive digital cameras lack zoom features or a zoom lens, and even then, most have add-on products you can buy to give your camera zoom capabilities. Some offer only small enlargement ratios, such as 2:1 or 3:1, in which zooming in closer produces an image that is twice or three times as big as one produced when the camera is at its beginning zoom setting. More expensive cameras have longer zoom ranges, from 4:1 to 10:1 and beyond.

In addition, there are two ways to zoom in on a subject with a camera offering zoom functions. One is optical zoom, the camera uses its internal hardware to produce the magnification. This produces the sharpest enlargement during picture taking.

Digital cameras also feature digital zoom, in which the magnification is produced by using crude interpolation techniques. Remember from our October 2004 newsletter that interpolation is a process that computes pixel color values between the pixels that already exist and uses that information to produce the missing pixels in an enlargement. Digital zoom is much less sharp than optical zoom because digital zoom uses the same crude techniques that photo enlargement software uses, bi-cubic interpolation or worse. Indeed, you can get much better results than most digital zooms by using Imagener - simply take the picture at your camera's maximum optical zoom setting, then enlarge the image with Imagener.

Do not confuse optical zoom with digital zoom. Digital zoom can be used to crop a picture on the camera's screen. To improve and make more impressive product descriptions, camera manufacturers sometimes multiply optical zoom by digital zoom, calling it total zoom. It is a meaningless number and a sales tactic (see examples to the right). Concentrate on optical zoom properties when shopping for digital cameras only.