A  photographic camera is a device used to record a permanent image of an object on a photographic film or a photographic plate. It is based on the principle that if an object is kept beyond 2F of a convex lens, a real, inverted and diminished image is formed between F and 2F on the other side of the lens, where a photofraphic film is placed.  The human eye and the camera are similar in many respects, and different in others.