In cinematography and photography, pre-flashing is the exposure of the

film A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...

or other photosensor to uniform light prior to exposing it to the scene to be imaged. This adds a bias to the overall light input recorded by the sensor. It is sometimes used for artistic effects, as it can be used to add a colour cast to shadows without significantly affecting highlights. It is also used in fields such as astronomy to bias CCD image sensors into a linear region, improving their low-light sensitivity.

See also