Film grain

Grain or film grain (English grains) is called in the photography, the smallest structures of the developed film that are visible only under high magnification. Photo Chemically, these are aggregates of finely divided silver particles that are responsible for the disruption evenly blackened faces.

The fine - or coarse-grained is very dependent on the type of film, but also of the development conditions. Films with low light sensitivity, ie with low ISO values ​​, are much finer-grained than highly light sensitive films with high ISO values ​​in the rule. The color intensity of the possible range of contrast and maximum density of highly sensitive films differs from films with low or medium sensitivity from visible. However, it should be noted that this relationship is valid only for film materials which have the same technical standard, modern movies with ISO 400 can definitely less annoying than having grain medium speed films (ISO 50 to ISO 100) from the 1970s.

Similar to the image noise in digital media, the film grain limits the resolving power of a photographic film, which is why highly sensitive film material is more suitable for subjects that do not require high detail.