CLAPPERBOARD - WHY ?
Clapperboards match / synchronise picture and sound so that the audio (dialogue) and associated action happen at the same time (synchronise). The clapperboard does convey other information, both visual and audio (see below).
Board identifying a second camera (cam B) filming at the same time as the first camera (cam A), but from a different angle.
TO CLAP OR NOT TO CLAP
Although camcorders now lock the sound to the picture, other filming equipment still needs a separate source for high quality audio (i.e. when filming with a DSLR (Digital Single Lens Reflex) camera with digital video capability).
A clapperboard (it is also known as “the slate”) has information written on it as well that relates to the shot being filmed. This information would include:
Scene number = The scene within the script that the action being filmed relates to.
Shot number = The shot number that relates to the storyboard. Or the chronological sequence shots are filmed, with details of the actual storyboard shot made on the camera log.
Take number = Indicates how many times you have filmed a shot. Take 1 for the first time filmed and then 2, 3, and so on. If using a camera log you can note which takes have mistakes, which are NG (No Good) and which ones you liked.
An audio cue “mark it” used to denote the point when the clapperboard is used and (both visual board and spoken details) at the front (or back) of a shot. The sync mark is when the clapperboard snaps shut.
Front slate / clap for sync.
Performer slates / claps shot for ease.
FRONT OR BACK SLATE
Sometimes it isn’t possible to use a clapperboard at the start of a shot, instead it is used at the end of the shot while the camera is still running, this is called an end slate. It is different because the clapperboard would be held upside-down, to indicate the end.
Front slate for mute take (no audio recorded), therefore the board is held open (or closed) and not “clapped”.
End slate for mute take.
NO NEED TO CLAP
Even if it isn’t necessary to use a clapperboard you will want to identify a shot in the same way you would with a clapperboard. The only thing missing is the sync mark (clap).
Even with a clapperboard, if there is no slate the clapper is just held open to denote a no audio take. Forms of visual shorthand like this convey more information then just scene, shot and take.
Front and end boards of prop shot without sound, slated between actual shots.