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Light valve
A light valve or light vane is a device controlling the light output of a motion picture printer. Three light valves are used in an additive printer head to control the colour quality.
In sound, a light valve is a device that produces a variable width light beam in response to electrical sound signal in a sound camera. 1
References
1 Case, D., 1985, Motion Picture Film Processing, Media Manuals, Focal Press, London, Boston
The National Film and Sound Archive of Australia acknowledges Australia’s Aboriginal and Torres Strait Islander peoples as the Traditional Custodians of the land on which we work and live and gives respect to their Elders both past and present.