Motion picture camera with fade-in and fade-out effects during long-term exposure

摘要

A motion-picture camera switchable to long-term exposure, in the presence of insufficient illumination for normal filming, has a photodetector which in the long-term mode controls a timing circuit measuring the length of an exposure period during which the camera shutter is arrested in an unblocking position, that period varying inversely with the detected intensity of incident light. In order to provide a fade-out effect at the end of a scene taken in this manner, the exposure period is progressively shortened--or the diaphragm aperture is progressively reduced--in discrete steps during successive shutter cycles to substantially complete cutoff. For fade-in at the beginning of a scene filmed with long-term exposure, the opposite procedure is followed.