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How It Works - Zoom Lenses


How It Works - Zoom Lenses

Nearly all digital cameras, including even the most basic entry-level models, are equipped with compact but powerful zoom lenses. We’re so used to using them every day that we seldom stop to consider just how remarkable they are or exactly how they work. We just push a button and the image on the screen gets larger or smaller at our command.

Despite the advances in optical quality and miniaturisation in recent years, zoom lenses are not a new invention. In fact simple zoom lenses were used as early as 1834 in astronomical and naval telescopes to vary the magnification of the image. The first telephoto lenses also included moveable elements to change the focal length of the lens. The first practical zoom lens that corrected for optical aberrations was introduced in 1932, and the first production zoom lens for 35mm cameras was introduced in 1959.

Since then, advances in optical design, particularly the use of computer-aided design, has made the development and construction of zoom lenses much easier, and they are now used widely in all types of photography.

Modern zoom lenses are marvels of advanced optical engineering. The demand for ever more compact digital cameras has put increasingly difficult demands on the camera designers. Components such as batteries and LCD screens are large and take up a lot of space inside the camera body, so one of the only ways to save space is by making the lenses smaller. Today’s lenses are a fraction of the size of those of just few years ago, but thanks to advances in technology, they perform as well as or even better than older lenses many times their size.


August 1, 2013, 2:49 pm

This would make more sense if the figures were the right way round. The top one is narrow angle and the bottom one is wide field.

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