Synchronised Sound: Double System

In cutting a film you will also have to prepare the soundtrack. Again you must have suitable materials to work with.

Cutting sound

A 16mm film can be shot without any sound at all, Documentary films are often shot “mute”. The whole soundtrack is prepared during cutting, An alternative is to shoot with synchronised sound. What is synchronised sound, and how is it filmed?

Synchronised sound exactly matches the picture to which it refers. If a shot shows a man hitting a nail with a hammer, the bang on the soundtrack will exactly match the point at which the hammer and the nail touch in the picture, But if you are cutting sound and picture on separate pieces of film, as is usually the case, you will find that they cease to match if you move either sound or picture independently. Sound and picture will then be “out of synchronism”.

Double system shooting

Synchronised sound is normally recorded on a tape recorder locked to a camera by a synchronising pulse. There is not always a visible connection between the camera and the recorder. The camera generates a pulse (usually 50 or 60 cycles) which is recorded on the side of the sound recording tape. The sounds being recorded occupy the other side of the tape. When filming is complete the tape is rerecorded on perforated magnetic film and, once this is done, the pulse is used to keep tape and the magnetic film in synchronism. This system, snooting the picture on mute film stock and simultaneously recording synchronised sound on tape, is known as double system shooting. By using crystal synchronising apparatus it is possible to synchronise one recorder and a number of cameras. There are many possibilities and, having sound and picture on separate pieces of film, you will be able to enjoy far more cutting freedom. An alternative is single system sound shooting.

SYNCHRONISED SOUND; RAW MATERIALS TO WORK WITH

Double system shooting
Location sound is normally recorded on 1/4in tape (A) locked to the camera by a synchronising pulse. After shooting, this pulse is used to govern the speed of a recorder re-recording the tape on perforated magnetic film (B) ready for cutting. Picture is normally shot on double perforated film (C) which must be processed (D). The processed original can then be contact printed on positive stock to make a rush print which can be used for cutting (E).