Film grain

Optical texture of processed photographic film

Film grain or film granularity is the random optical texture of processed photographic film due to the presence of small particles of a metallic silver, or dye clouds, developed from silver halide that have received enough photons. While film grain is a function of such particles it is not the same thing as such. It is an optical effect, the magnitude of which depends on both the film stock and the definition at which it is observed. It can be objectionably noticeable in an over-enlarged film photograph.

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