A Studio-Type and a Portable-Type System for Synchronizing $\frac{1}{4}$-Inch Magnetic Tape with Perforated Motion-Picture Film

Edward P. Kennedy

The method of utilizing synchronously driven toothed sprockets engaging complementary film sprocket holes for sound-film production is, of course, an old technique. The introduction in 1947 of sound magnetic tape having a thin and easily torn base of cellulose acetate made sprocket holes highly impractical. The two systems discussed in this paper employ magnetic equivalents of sprocket holes recorded along the tape simultaneously with the recorded sound and at the exact time of frame exposure in the camera. The “latent magnetic sprocket holes” are later reproduced to serve as a master speed control device to govern the speed of the picture film through playback equipment.

Print ISSN
Published
1958-02
Content type
Original Research
DOI
10.5594/J06228