(The EF 28-105mm f3.5-4.5 II USM lens, is an excellent general-purpose lens. It covers a good range of wide-angle and short telephoto focal lengths in a compact unit)
A zoom lens gives you the equivalent of several lenses in a single package. Instead of buying 28mm; 35mm, 50mm, 85mm and 100mm lenses, you can buy a 28-105mm lens. Not only is this less expensive, it is also a lot lighter to carry. With just two zoom lenses, such as a 28-80mm and a 75-300mm, you are ready for most subjects. A zoom lens also offers you settings between the focal lengths available in prime lenses – 32mm or 183mm, for example.
Generally, prime lenses have a wider maximum aperture than zoom lenses. Wider apertures let more light through the lens, which means you can use a faster shutter speed for the exposure. This is an important consideration when choosing a telephoto lens, because a faster shutter speed helps to reduce the effects of camera shake. A wide aperture is also invaluable when shooting in low light without flash – at a floodlit sports event, for example, or with ambient light indoors. A prime lens is also the only choice for super-telephoto lenses. The maximum focal length found in an EF zoom is 400mm, while prime lenses are available up to 800mm. In terms of image quality, some prime lenses are better than zooms, though the difference is not significant focal lengths in a compact unit. for many users.