In a movie production, a movie clapper is a film equipment that is used by a member of a movie crew to mark specific scenes and takes on film for the camera. Marking scenes with the movie clapper assists the film editor in synchronizing the picture and sound in the film being produced. This movie-making tool is also referred to as clapboard, clapperboard, or slate board. There are two major components of a clapper: the slate and the clap stick. The slate holds key production information used to identify scenes and the clap stick is used to align sound with picture during editing.
During the early days of film production, one movie crew member holds the slate for the motion picture camera while another person clapped the sticks together for synchronization. The two components were later combined into a single unit known as the movie clapboard to make the job easier for just one person to handle.
People who are unfamiliar with film work may think that this film clapboard is nothing more than a signage of sorts that identifies the current scene that is being shot. This is because most of us are used to the mechanism of the camcorder, which records video and sound on the same tape. Filming a movie is a totally different matter because the pictures and sounds are recorded independent of each other. This is where a clapper is needed.
The clapboard slate contains the date, title, director and scene information (scene and take number, camera angle). The clapsticks provide specific audio markers, which are very important especially when multiple cameras are used in filming. The information on the slate helps the editing team identify which sound sequence should go with a particular shot and the markers provided by the sticks signal the exact moment that a take begins, thus making sound synchronization easier for scenes with multiple takes.
And while the slate board already contains the information as to which scene is being shot and what particular camera angle is being used, a verbal slate is also needed for audio purposes. A person states the scene and take number to make it easier for the laboratory technician to identify the shot. This creates less confusion for the technician and ensures that the dailies are released on time.
The first movie clapperboard was made up of a wooden chalkboard with a hinged clapstick attached on top of it. With the passing of time, this has evolved into a pair of wooden sticks attached to the top of a whiteboard or acrylic glass slate. The crew member uses a dry erase marker instead of chalk to write on this white acrylic board which was also easier to read with minimal light. Today, the dry eraser movie slates are preferred by independent filmmakers because the information written on it is more legible and it is more practical to use.