Zoom Camera

zoom lens is a mechanical assembly of lens elements for which the focal length i.e. angle of view can be varied, as opposed to a Fixed Focal Length (FFL) lens.

A true zoom lens, also called a parfocal lens, is one that maintains focus when its focal length changes. A lens that loses focus during zooming is more properly called a varifocal lens. All lenses (mainly, super zoom lenses) are a compromise of features-size, weight, price, focal length range, image quality, autofocus performance, build quality and other features