Synchronized magnetic tape recording

MOTION PICTURES have obviously required synchronized sound to match picture and words in all released prints. Perforated film has been the usual answer to this requirement ever since sound was added on film. But now that magnetic recording has shown such tremendous opportunities in quality and economy, the use of this facility for sound for motion pictures is immediately attractive. One answer has been, of course, the use of normal photographic film stock, coated however with iron oxide instead of the usual silver emulsions. And again perforations accomplished the lock-in. But 1/4-inch tape without sprocket holes is so much more flexible because of its thinness, takes up so much less space, and gives top quality with so little effort that its use would certainly be ideal if synchronism might also be accomplished.