Concept in Definition ABC

Zoom is an English word that has already transcended its own borders and is used to designate the special telephoto lens distance variable focal length, either from a photographic or cinematographic camera. Depending on the direction given, that is, forward or backward, the image in question can be zoomed in or out.

The origin of this object widely used in areas such as Photography, television and movie theater takes us quite a bit back in time, more precisely to XIX century. Telescopes began to use moving lenses that allowed the aforementioned modification of the focal length. In these early days it was always necessary to refocus on each chance that the focal length was changed.
It would only be at the beginning of the 20th century, in 1902, when a zoom was achieved that maintained the focus even varying the focal length; the patenting of the same was responsibility from Clile allen.
Meanwhile, the first zoom lens produced at scale industrial would hit the market a few years later, in 1932.

On your side, the zoom factor, will be the quotient between the maximum and the smallest possible focal length, for example, the 2x zoom is a zoom in which the maximum focal length is twice the minimum focal length. And when the zoom exceeds 5x you are already in a position to speak of super zoom.

The power zoom it's a type of motorized zoom, the lens groups will scroll automatically just by pressing a button on the camera in question.

And two other types of regular zoom are, on the one hand, the optical zoom, which works through movement of the lenses and on the other hand the digital zoom which is the one that cuts the margins and enlarges the central part of the image, using a single part of the sensor and reducing the quality.

Zoom lenses turn out to be a very practical and economical alternative to the game of different fixed focal lenses, since with them one will avoid having to continually change the objectives.

And also, the term zoom has become very popular as a consequence that it is the title of one of the songs of the Argentine pop group Soda Stereo, which has been composed by the leader of the band Gustavo Cerati and that makes up the album Dream Stereo.