cinematography Cinematography (from ancient Greek κίνημα, ''kìnema'' "movement" and γράφειν, ''gràphein'' "to write") is the art of motion picture (and more recently, electronic video camera) photography. Cinematographers use a lens to foc ...

and

photography Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employe ...

, pre-flashing is the exposure of the film or other

photosensor Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There is a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or by ...

to uniform

light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 te ...

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 A colour cast is a tint of a particular colour, usually unwanted, that evenly affects a photographic image in whole or in part. Certain types of light can cause photographic film, film and digital cameras to render a colour cast. Illuminating a su ...

shadow A shadow is a dark area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volume behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, ...

s without significantly affecting highlights. It is also used in fields such as

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

to bias CCD image sensors into a linear region, improving their low-light sensitivity.

See also