Movie Making Manual/Clapper board

You can use a clapper board to identify which scenes you wish to include. For example, you could write the TAKE number and the SCENE number, so while editing you can just select the thumbnail with the information you selected to include in your final movie, and trim the scene and add it to the final movie. In North America, the clapper is referred to as a slate. It's use is as follows. The assistant cameraperson "AC" asks the script supervisor which scene and take is up. This is written on the slate with either chalk or marker. If there is sound recorded, then the clapper sticks are hit together so the editor has both a visual cue (the first film frame with the sticks together) and a sound cue (the clap). It is often perceived that the slate is always clapped, but for much of the film there is no sound (only necessary for synronizing the actors lips with their dialogue) and the slate is put in frame closed. Slating is the last thing that happens before the action can start, however in some circumstances where it's unclear when the event might happen (as an explosion) the camera will be slated or "marked" at the end of the action, called an "end-slate."  