Zoom Lenses- Caterina Franciosi

There are two different types of lenses according to the difference in the focal length, which sets the angle of view of the camera. Prime lenses have a fixed focal length, whereas zoom lenses have variable focal lengths. Therefore, they are more properly called varifocal lenses. Thanks to this feature, zoom lenses allows to photograph a variety of subjects such as landscapes and portraits without the need to change lenses for different situations. This advantage allows to save time and reduces the risk of damaging the camera's box or sensor with dust coming inside.

Sources: http://www.nikonusa.com/en/Learn-And-Explore/Article/g3cu6o2o/understanding-focal-length.html#!

Caterina Franciosi