the sensitivity to light of a photographic film, specified in terms of the film's ISO rating
2.
the rate at which the film passes through a motion picture camera or projector
film speed in American English
noun
Photography
the sensitivity of a film or paper to light, measured by an ASA or DIN index, which assigns low numbers to slow film and higher numbers to faster film; speed
Word origin
[1910–15]This word is first recorded in the period 1910–15. Other words that entered Englishat around the same time include: blackout, flashback, functionalism, grass roots, insulin
Examples of 'film speed' in a sentence
film speed
The film speed is set to approximately the speed of the athletes.
Times, Sunday Times (2012)
Moreover, in projection, the film is slowed down from the conventional film speed of 24 feet per second to a time-stretching 16 fps.