The motion picture camera (see under camera) was developed from simple multi-image devices that, when spun or flipped, displayed the parts of a continuous movement, which, combined with the ocular principle of persistence of vision, produces the illusion of movement. The camera takes a series of photographs on negative film; when the positive is moved through a projector at a speed consistent with that of the camera, they throw a realistically perceived moving image on a wall or screen.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.