Combined Prints: Optical Sound

How do you make a sound negative and prepare it for printing? You must first send the master magnetic track off to a sound recording studio to be “transferred” to optical sound. Before you send it off, you must mark an audibly recognisable point by replacing one frame of the leader with a frame of thousand cycle tone. You might perhaps remove the figure 3 on the leader and replace it with a frame of tone. This frame will reproduce as a bleep — and will give you a point to refer to on the sound negative. The bleep will immediately be recognisable as one frame of closely spaced lines.

Comopt copies : advancing sound for printing

When the optical sound neg has been developed and delivered to you in the cutting room you will have to synchronise it to the neg cut camera original. To do this you will need to use a synchroniser, a cement joiner and work at the cutting bench. Now you must remember where you put the frame of tone on the leader of the master magnetic. You replaced the figure 3 on the leader with a frame of thousand cycle tone. So, look for that frame on the sound negative. Remember it will appear as one frame of closely spaced lines. When you have found it, put it in the synchroniser opposite the figure 3 on the leaders of the picture film. Sound and picture are now in level synchronisation, as they were in the dubbing theatre. But remember, sound must be advanced on a combined print. So, take the optical sound negative out of the synchroniser and move it 26 frames towards the head of the roll. It is now in synchronism for 16mm comopt printing. Wind back to the start of the roll and mark start marks on the head of all the rolls writing the words “16mm printing sync — start — roll one of one — head”. You can then wind carefully through to the end of the film and put end synchronism marks on as well identifying them as “16mm printing sync end. Reel one of one”. Sound and picture can then be sent off to the laboratory for printing.

PREPARING COMBINED SOUND COPIES

1. Level synchronisation
The A & B rolls shown are in level synchronism with the magnetic track. Before you can make a combined optical sound print the magnetic must be re-recorded and the resulting sound neg advanced.

2. Advancing optical sound for printing
The tone on fig 3 of the leader appears as a visible bleep. For printing it must be advanced by 26 frames. Using a synchroniser, put the bleep opposite ‘3’ and then move the sound neg 26 frames towards the head of the roll. Put “start” marks on the camera original and the sound neg marking them “16mm printing sync, Start”. Comopt copies can now be printed.