Why should lenses be coated?

Lenses are composed of lens pieces, but the light will be reflected and absorbed on each lens, resulting in insufficient light. Coating can work on various colors of light. Usually, different materials are used to repeatedly plate films with different thicknesses on the lens surface, which can greatly improve the light transmittance of the lens.

There are two fingers in film and television, one refers to the optical components used to produce images such as movie cameras and projectors, and the other refers to the continuous pictures taken from power on to power off. Sometimes the fragment between two splicing points is also called a shot, and the first finger and the second finger are two completely different concepts. In order to distinguish the two, one finger is often called an optical lens and the second finger is called a lens picture.