analyse à spot lumineux

CONT: The first constant speed telecines used the flying spot scanning principle. A CRT [cathode-ray tube] produces a small spot of white light which is focused on the film. The spot is driven back and forth across the tube by a sawtooth waveform and consequently scans the film transversely. The film modulates the intensity of the light passing through and sensors on the other side of the film produce a video output signal.