photograph

n. a still picture formed on a light-sensitive surface using an optical system and fixed by a photochemical process an image rendered using a camera

Notes

Most traditional photographic processes use a silver halide as the light-sensitive material, although light-sensitive salts of copper, iron, and uranium have been used as well. The silver halide is reduced to metallic silver in black-and-white photographs and is used to form a dye in color photographs. In the nineteenth century, collodion was commonly used as a binder for negatives, prints, ambrotypes, and tintypes, and albumen was the most common binder for prints. Most modern photographic processes use gelatin to bind the silver halide to a film, paper, or glass support. Technically, a photograph1 is distinguished from a print1, in which the image is formed mechanically rather than photochemically. However, print3 is commonly used to describe images originally made with a camera but reproduced using a photomechanical process, such as a halftone or a Woodburytype. Such images were, at some point, a photograph before reproduction. However, digital photographs now capture and record images that are printed using a nonphotographic print process.