Jam sync timecode locks location audio to camera via a brief cable handshake and periodic re-checks

When recording audio in sync with a film camera, the standard practice is ‘jam sync’: the audio recorder receives timecode from the camera for a short period (seconds) via a cable, then the two devices free-run independently, using their own clocks to maintain the same time address. Because each device has a slightly different clock, the two will drift over time; periodic re-jams (every couple of hours) keep them aligned. Alternatively, ‘record run’ timecode keeps the timecode counter running only when the camera is recording, relayed via radio link when cable is impractical. The connection typically uses a 5-pin Lemo connector.

Examples

Watson jams Sonosax SX-R4+ to camera timecode via 5-pin Lemo at session start; re-checks alignment every 2 hours. For remote situations, switches to Record Run timecode via radio link.

Assessment

Explain why jam sync timecode can drift between audio recorder and camera over a long take, and describe the standard remedy used in location recording.