Cinematography (from ancient greek κίνημα, kìnema “movement” and γράφειν, gràphein “to write”) is the science or art of motion-picture photography by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as film stock.
Cinematographers use a lens to focus reflected light from objects into a real image that is transferred to some image sensor or light-sensitive material inside a movie camera. These exposures are created sequentially and preserved for later processing and viewing as a motion picture. Capturing images with an electronic image sensor produces an electrical charge for each pixel in the image, which is electronically processed and stored in a video file for subsequent processing or display. Images captured with photographic emulsion result in a series of invisible latent images on the film stock, which are chemically “developed” into a visible image. The images on the film stock are projected for viewing the motion picture.
The word “cinematography” is based on the Greek words κίνημα (kinema), meaning “movement, motion” and γράφειν (graphein) meaning “to record”, together meaning “recording motion”. The word used to refer to the art, process, or job of filming movies, but later its meaning became restricted to “motion picture photography”.