filmgrain

Film grain refers to the visible granular texture characteristic of many photographic films and motion-picture emulsions. It arises from the random distribution and varying size of silver halide crystals (and their development products) within the emulsion. The texture becomes more pronounced as the effective ISO increases, or as development is pushed, making grain a defining attribute of traditional film stock.

In practice, grain appears as discrete particles of varying density that can resemble salt-and-pepper noise but with a more organic, clumped appearance. Different film stocks produce distinct grain patterns, with finer grains on lower-ISO emulsions and larger, often more irregular grains on higher-ISO or aggressively developed stock. In color film, grains relate to the dye layers, but the visible texture is the aggregate of grains across channels.

Grain is often associated with the aesthetic qualities of film, contributing warmth, texture, and perceived depth. Some filmmakers embrace grain as a deliberate stylistic element, while others seek to minimize it through improved stock, controlled development, or digital noise reduction. In digital workflows, film grain can be added synthetically to reproduce the classic film look or retained from scanned archival prints to preserve historical texture.

Grain behavior is influenced by exposure, lighting, development chemistry, and printing or scanning processes. Restoration and remastering may reduce or preserve grain depending on artistic goals. Grain and noise are technically distinct: grain is the physical structure of the emulsion, whereas digital noise is a sensor-related artifact; however, modern post-production can blend the line by adding or removing grain to achieve a desired balance between texture and sharpness.