Digital Photography Technology

A zoom lens is the most desired lens when a person purchases a camera with an interchangeable lens system. The reason for wanting a zoom is the advantage of changing the focal length of the lens while composing the picture. A single zoom lens will take the place of several fixed focal length lenses.

Early zoom lenses were not as sharp as a fixed focus lens and professional photographers would not consider using them. They had two adjustments, one to change the focal length and the other to focus. With the advent of computer aided design, a zoom lens has come a long ways to become the lens most amateurs prefer to use.

There are a number of down sides to these lenses. Weight is one. A zoom will be considerably heavier than a fixed focus lens and also slower in speed. Many zooms also get slower as the focal length gets longer. For those still who use an exposure meter, this is a disadvantage. Most zooms are not as fast as fixed lenses, and if they are, they are extremely heavy and expensive.

Other disadvantages are that the front ring on a zoom will rotate on some lenses. This creates a problem when using certain filters, such as graduated neutral density and polarizing filters. Focusing up close is not possible as it is with a fixed focus lens.

Deciding which lens you need will be a trade off. It all depends on the photographer and the type of photography that you do. If it is macro photography, a fixed, fast, single lens is required. Sports photographer, a zoom is a definite advantage

You will also find Zooms come in a variety of different ranges. They will start at 12-24, 28-80, 80-200 and 100-300 mm. Every manufacturer make one is a slightly different range and speed.

What ever you purchase now, you will always get another one later.