The Clapperboard Explained

We see them all the time on movie out-takes, but what's the actual purpose of the clapperboard (sometimes called a slate), and why is it clapped together? The main function of a clapper board is to allow the video and audio, which are recorded separately, to be synced during editing. The "clap" noise registers on the audio recording and which can then be timed to match the physical closure of the clapperboard on film, insuring the rest of the take is synced.

The board portion of the clapperboard is used to record information about the scene for reference later. Originally, the clapper and the board were separate parts. One crew member would hold the board, or slate (which was an actual piece of slate from a chalkboard), in front of the camera. Another crew member would take two pieces of hinged wood and clap them together in the camera's view. The decision to make them one was an obvious evolution.

Modern clapperboards are made out of a whiteboard material to allow writing to be erased. Highend models have LED displays built in which display the date and time. The time is then synced with all the equipment on set to ensure it's always correct to the millisecond (and removes the need to constantly update it by hand). The clapper portion of the of board is traditionally covered with black and white strips to ensure visibility. More modern ones are covered with a series of multi-colored stripes which allow the film to be color calibrated.

  Subscribe to our feed