Finding and Maintaining Synchronism
Some modern cameras employ an automatic sync marking device. When the camera has run up to speed a light built into the camera automatically fogs a small number of frames and a bleep is simultaneously reproduced on the sound recording. The exact system used tends to vary from one make of equipment to another. However, you will frequently find that where automatic synchronising equipment has been used the camera crew shooting the material have not bothered to provide clapper board identification. You will have to synchronise sound and picture by aligning the bleep on the sound with the clear frames on the picture. You will still need a clear aural identification of the sound shot. You can then often synchronise sound and picture by aligning the end of the bleep on the sound with the end of the clear (fog) frames of the picture. Automatic sync systems are notoriously unreliable. A weak camera battery can move the sync point by several frames so, though I have recommended aligning the last fogged frame of picture with the end of the sync bleep, this should not be regarded as a hard and fast rule.
Intercutting sync and mute takes
If the film you are cutting has been shot with synchronised sound for every scene you will be able to cut sound and picture simultaneously, using either a synchroniser or a motorised editing machine. Comparatively few films are shot with sync sound throughout and you may well find that you have some shots which are sync and some which are mute. How do you join the two together? Again you should use a synchroniser or a motorised editing machine, cutting sound and picture simultaneously whenever synchronised sound shots are involved. Where there is no sync sound, cut the picture on its own and build up the soundtrack by using spacing. Spacing makes no sound and if you use the same length of spacing as the mute shots in your reel of picture, synchronised sound shots on either side of the gap will remain in synchronism. In the example shown on the facing page, the film starts with a synchronised sound take. Then there is a mute sequence. The soundtrack has been built up by using spacing. When the next synchronised sound scene begins we have cut out of the spacing and into the sound again. Spacing ensures that the sound remains in synchronism from the head of the roll.
INTERCUTTING SYNC AND MUTE TAKES
Where sync and mute scenes are intercut, spacing should be used to preserve synchronism from the head of the roll.