Sound follower

A sound follower, also referred to as separate magnetic, sepmag, magnetic film recorder, or mag dubber, is a device for the recording and playback of film sound that is recorded on magnetic film. This device is locked or synchronized with the motion picture film containing the picture. A sound follower operates like an analog reel-to-reel audio tape recording, but using film, not magnetic tape. The unit can be switched from manual control to sync control, where it will follow the film with picture.

Many motion picture cameras do not record audio sound on the film, so in professional film production, there is a need to have the sound recorded and played back on a device that has a double-system recording to tapes, either DAT or Nagra, and then transferred to 16mm or 35mm separate magnetic film. The sound recording would then be synchronized with a movie projector or a telecine. Either 35mm film or 16mm film that is fully coated with a magnetic material can be locked, sprocket hole by sprocket hole, to the film with the picture image. On the set, a clapperboard is used to mark the spot where the sound and picture will later be synced.

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