A Synchronization Control Unit for Super-8 Sound Recording, Editing and Sound Transfer to Magnetic-Striped Film

An electronic synchronization control unit was built for two-strand sound recording, two-strand editing of magnetic sound tape and picture, and automatic transfer in synchronism onto striped film. It ensures synchronism even when the tape recorder and film projector used in this procedure are started separately. The control unit is based on an electronic counter circuit, which counts individual synchronization pulses recorded on the lower half of the tape and individual film frames as they pass through the film gate of the projector. Although our system was built for super-8 equipment, the method is applicable to any film format. The heart of the control unit is a 12-bit electronic counter. In two-strand synchronous image and sound recording, sync pulses are recorded by means of an intermittent camera switch and a tone generator. In two-strand editing the unit detects the difference in either direction (maximum 2048 frames) between synchronization pulses recorded on the sound tape and film frames passing through a projector. A light emitting diode indicates whether the sound is ahead of or behind the picture. For synchronized transfer of sound from tape to striped film, the circuit automatically matches by feedback control the tape speed to that of the projector used.

Print ISSN

0036-1682

Published

1978-03

Content type

Original Research

DOI

10.5594/J17411