Automatic colour film colour correction - uses grey wedges recorded in film sound track for TV reproduction

摘要

A colour correction system for colour film shown on TV employs an optical system built into the camera. To derive a colour correction criterion from the light at the scene. This optical system generates a sharply focussed, rectangular beam of light whose intensity is kept constant. A grey filter (19) is inserted into this beam at the colour camera stepping frequency. A series of grey wedges synchronous with the colour picture series is recorded. During picture reproduction, light pulses scanned from these wedges are converted by narrow band filters (R,G,B) for primary colours red, green, and blue and by a photocell into consecutive and recurring chronimance signals red, green and blue. They are used for automatic colour control of the t.v. colour film pick-up.