Zoom is a magnification function of images, graphics or photos and a software for online meetings. As an image function, Zoom is used in graphics programs to continuously enlarge images or image details. This magnification function is known from digital cameras, camcorders, projectors and video cameras
. A distinction is made between optical and digital zooming. Opticalzooming
isperformed via the optical lens system by changing
the focal length
from a wide focal length to a telescopic one.Optical zooming does not affect image quality in any way, even when the longest possible focal length is selected. The ratio between the largest and smallest focal length is the zoom factor. For example, if the smallest focal length is 38 mm and the largest is 190 mm, the zoom ratio is 5. During projection, zooming reduces the projected brightness. The higher the zoom factor set, the lower the light output
per unit areadigital zoom. This is an electronic magnification function in which the existing image resolution is not changed, but the magnified image section deteriorates in image quality with increasing magnification without additional image detail.