Buzz on film -[ HMM ]-

(No, not the Disney/Pixar computer-animated character.)

 

This is buzz track, an alignment film for 35mm optical soundheads. Each toothed pattern on the sides of the black stripe produces a square wave, which appears as a sharp buzzing noise when played through speakers. (By the way, playing a square wave through a speaker, except at a very low volume, is an excellent way to destroy it.) An oscilloscope is recommended instead of speakers for the task.

 

The track is spaced so that when the soundhead's lateral (left/right) guide roller is adjusted properly, neither track should be picked up. A higher-pitched buzz (and, possibly, a motorboat-like sound from the sprocket holes) will occur if the film is guided too far leftward; too far to the right, a lower-pitched buzz will be generated.

Done