photographic emulsion

A photographic emulsion is a light-sensitive material, typically a gelatin gel containing suspended silver halide crystals, such as silver bromide. When exposed to light in a camera, these crystals undergo an invisible change, creating a latent image. This latent image is distinguishable only by its ability to be converted into metallic silver by developing agents.12

Introduced around 1880, the gelatin process revolutionized photography by allowing sensitized emulsions to be dried and stored, eliminating the need for a darkroom at the time of exposure. This superseded earlier methods like the wet collodion process. Gelatin remains the standard binder for silver halide crystals in photographic film.34