Sound and Image Synchronism - Text 1
From cinema’s earliest years there have been experiments in recording and projecting synchronous sound[1]: it was possible to operate at exactly the same speed two mechanical devices, a camera and a sound recorder, driven by the same spindle. On the other hand, as soon as one uncoupled the two devices to make the shooting mobile, each mechanical motor ran at its own speed. The devices’ metal cogs would expand and wear down, making variations inevitable: with a few one-hundredths of a second between the recording of the image and that of the sound, synchronism is lost. In the early years of talking cinema, synchronism was obtained easily in the studio. The frequency of the electrical current’s oscillations was used to coordinate the speed of the two motors: one driving the camera and the other the sound recording equipment. Taking this cumbersome material out of the studio required a sound truck.
