thumb|right|Digital facsimile of a clapperboard
A clapperboard, also known as a dumb slate, clapboard, film clapper, film slate, movie slate, or production slate, is a device used in filmmaking, television production and video production to assist in synchronizing of picture and sound, and to designate and mark the various scenes and takes as they are filmed and audio-recorded. It is operated by the clapper loader. It is said to have been invented by Australian filmmaker F. W. Thring. Due to its ubiquity on film sets, the clapperboard is frequently featured in behind-the-scenes footage and films about filmmaking, and has become an enduring symbol of the film industry as a whole.
History
thumb|Clapperboard
In the silent era the principal requirement of film stock identification during a day's shoot was the slate.
The clapper as two sticks hinged together is credited to F. W. Thring (father of actor Frank Thring), who later became head of Efftee Studios in Melbourne, Australia. The invention, however, is thought to be the responsibility of two of his sound engineers: Alan Mill and Harry Whiting. The clapperboard with both the sticks and slate together was a refinement of Leon M. Leon (1903–1998), a pioneer sound engineer.
Description
A clapperboard is made up of a chalkboard, slate, or acrylic board, with a pair of clapper sticks positioned across the top. One stick is fixed to the upper edge of the slate, while the other is hinged at one end, allowing it to move. The slate typically displays the name of the production, along with details such as the scene and the "take" that is about to be filmed, as well as other relevant information; a camera assistant holds the clapperboard so the slate is in view of the cameras with the clapper sticks already open, speaks out information for the benefit of the audio recording, then snaps the sticks shut. Chalk or dry-erase markers may be used to write on the slate or whiteboard respectively.
The shutting of the clapper sticks is easily identified on the visual track, and the sharp "clap" noise is easily identified on the separate audio track. The two tracks can later be precisely synchronized by matching the sound and movement. Since each take is expressly identified on both the visual and audio tracks, segments of film are easily matched with corresponding segments of audio.
Methods were later developed to directly record sound to film as part of a single system integrated with the film camera (so-called single-system recording), which was most commonly used with small formats like Super 8 film. However, single-system recording did not render clapperboards obsolete. First, single-system recording of sound-on-film is "decidedly inferior in audio quality" to traditional double-system recording. Despite that, contemporary digital cinematography still relies upon double-system recording, which means that directors of professional-quality film and television productions still need to use clapperboards. The main reason is that the audio features needed for quality single-system recording are found only on midrange or "prosumer" digital cameras.
A clapperboard is generally used to identify all takes on a production, even takes that do not require synchronization, such as MOS takes, which have no sound. When a slate is used to mark an MOS take, the slate is held half open, with a hand blocking the sticks, or closed, with a hand over the sticks.
Operator
The clapper loader (or 2nd AC) is generally responsible for the maintenance and operation of the clapperboard, while the script supervisor is responsible for determining which system will be used and what numbers a given take should have. While these are usually fairly obvious once a system has been agreed upon, the script supervisor is usually considered the final arbiter in the event of an unclear situation.
Alternatives
Sometimes a "tail slate" or end slate is filmed at the end of a take, during which the clapperboard is held upside-down. This is done when the slate was not captured at the start of the take due to the camera being set up for the shot in such a way that the board cannot be captured, for example when a specific focus or frame is set up and cannot be altered until the take is complete. Tail slates are also commonly used when the director makes the decision that clapping a slate at the beginning of the scene would be distracting to the actor, such as when filming a highly emotional performance.
<gallery widths="194px" heights="194px">
File:Clapperboard, O2 film, September 2008.jpg|A Denecke clapperboard containing LED display with SMPTE Timecode and colored stripes on the sticks.
File:Хлопушка-нумератор.jpg|A clapperboard with a dry-erase display being used for a Russian-language film.
File:Clapperboardinuse.jpg|An acrylic glass clapperboard in use
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See also
- Slate (broadcasting), a title card listing important metadata of a television program, attached before the first frame of the program
- 2-pop