A clapperboard is a tool used in the film, television, and advertising industries to help with the synchronization of sound and film recordings. Because sound and film are typically recorded separately, careful matching is required during the editing process, or the final product will feel slightly off to viewers. It can be almost comical when the synchronization is bad, but even minor differences can be very confusing for viewers.
A clapperboard is made up of two parts: the clapper and the slate. The clapper is made up of two pieces of wood or plastic that can be snapped together to produce a distinct clacking sound that can be heard clearly on the sound recording. The editor can synchronize the sound and film recordings by matching the sound of the clack to the physical action on the screen. Clapperboards are sometimes given away as film production mementos.
The slate is used to keep track of details about the production, such as the title, director, and director of photography, as well as the scene. The slate also has the take number and camera angle written on it. People in the editing room can use this information to quickly figure out what they’re looking at by reading the clapperboard.
The film crew sets up the scene, writes the information on the clapperboard, holds the clapperboard up, and then turns on the camera to use a clapperboard. The information on the slate is usually read out loud before the clapper is snapped. The actors can then begin their performance. The sound on set is captured and recorded on one device, while the scene’s film is stored in the camera.
Clapperboards don’t have to be clacked in order to mark a scene. Digital slates, in which a timer is synchronized with the camera, are used by some filmmakers. The camera records the time on the clapperboard when it is held up at the start of the scene, allowing the editor to find the same point in the film or digital recording to synchronize with the sound later.
All of the information on the clapperboard is also recorded in the production’s continuity book, so that crew members and editors can look up details later. For instance, an editor looking for a specific scene to work on could look in the continuity book to see where it should be.