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A prime lens offers a single focal length; a zoom lens, a range of focal lengths. For example, a lens might zoom from 18 to 55mm.

In camera or lens advertisements, the zoom range is sometimes described in terms of an “x” factor, as in a 3x zoom. Here, the x means times, with the value indicating the difference between the shortest and longest focal length of the lens. So an 18–55mm lens boasts a 3x zoom, for example (18 × 3 = 54).

As a general rule, prime lenses equate to better-quality photos because a lens can be engineered to optimal performance at only a single focal length. That said, one of my favorite lenses is the super zoom; it has a monster focal length range — 18 to 400mm. Newer lenses perform better in this regard than those manufactured in the past.

Some fixed-lens cameras offer both optical and digital zoom. Optical zoom is a true zoom lens and produces the best picture quality. Digital zoom is a software feature that crops away the outside of the image and enlarges the remaining area, a process that lowers image quality. In other words, pay attention to the optical zoom specs and don’t be too impressed by the digital zoom range.