Movies

A plexiglass clapboard with scene details.

In motion picture and videotape production, a clapperboard is a device used to synchronize picture and sound; additionally the clapboard is used to designate and mark particular scenes and takes recorded during a production. Many other names are commonly used, including clapboard, slate, slate board, sync slate, sticks, board, and marker.

Traditional clapboards used to consist of a wooden slate and a hinged clapstick attached to the top of the slate. However, modern clapboards now generally use a pair of wooden sticks atop whiteboard or translucent plexiglass slates which do not require additional lighting from the camera side to be legible. Some versions are also backlit. In addition, expensive electronic SMPTE time code versions with LED numbers are available. The sticks traditionally are diagonal interleaved lines of black and white in order to ensure a clear visual of the clap in almost any lighting conditions, but in recent years sticks with calibrated color stripes have also become available. In some productions, particularly those created in the digital domain, electronically-superimposed versions of a clapboard have supplanted the real thing.

In use, the details of the next take are written on the slate of the clapboard. A verbal indentification of the numbers, known either as "voice slate" or "announcement", occurs after sound has reached speed. At the same time or shortly thereafter, the camera will run, and the clapboard is then filmed briefly at the start of the take and the clapsticks are clapped sharply as soon as the camera has reached sync speed. Specific procedures vary depending on the nature of the production (documentary, television, feature, commercial, etc) and the dominant camera assisting conventions of the region; therefore it is not possible to describe a definitive practice aside from the general principles.

Sometimes a tail slate or end slate is filmed at the end of a take, during which the clapboard is held upside-down.

Shooting information about the next take is written on the slate of the clapperboard. This includes the date, the production title, the name of the director, the name of the director of photography and the scene information - which follows two popular systems: American - scene number, camera angle and take number; e.g. scene 24, C, take 3; European - slate number, take number (with the letter of the camera shooting the slate if using multiple cameras); e.g. slate 256, take 3C. Often the European system will also include the scene number as well; however, a separate continuity sheet that maps the slate number to the scene number, camera angle and take number may be used if the scene number is not included on the slate. This is generally not as great a concern with short films, however.

The clapboard may have been invented by Frank Thring, head of Eftee Studios in 1920s Melbourne, Australia.^[1]