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 silent take (no audio recorded), therefore the board is held and not ‘clapped’ (unlike the examples above and below, normally when no audio is recorded - also known as a MOS shot - the slate would be held with the clapper closed).
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.
Below is a home-made shot ident board for a video shoot (mid eighties). It was used to identify shots like a clapperboard, but wasn’t needed to sync the sound and picture, because they are already locked together on tape by default.
Abbreviation for broken German expression ‘Mit-Out-Sprache’ (without speech). written in a clapperboard to denote no sound, or mute takes.
TIMECODE (DUMB/SMART) CLAPPERBOARDS
Many new clapperboards will include visible numbers (timecode) which (from left to right) display hours, minutes, seconds and frames. These clapperboards are referred to as ‘digislates’.
A ‘dumb’ slate (clapperboard) receives information from audio, camera, or other device to run the timecode. A ‘smart’ slate uses its own timecode.
In some cases the timecode (TC) number can be frozen when the clapper is ‘clapped’, in other cases it will zero.
There are now very simple forms of synching devices you can download for tablets and/or mobile devices. Of course they do not function ‘physically’ in the same way as a clapperboard, but offer alternative ways to sync picture and audio. The two examples here are android apps. The first ‘MARK’ (A) has a very minimal interface for scene, or shot. Camera A or B etc. and take number. When enabled it produces a tone and screen flash (mark) when the screen is touched. The second app * ‘CLAPPERBOARD’ (B) has a more busy interface with scene, shot, take and title entries. You can also input the frame rate and other environmental information. You can set how long before the clap will occur from the time you touch the clapper chevrons, before either the sound of a clap, or tone will be played and the screen will alter to identify the clap, along with the sound.
* In tests on an android phone the app ‘CLAPPERBOARD’ would intermittently lose the audio tone (sync mark).