Canon 312 XL-S - Manual (Page 67)

Filming begins with full pressure on the shutter
release lever. Use of the Canon Boom Microphone is
recommended if you want to move while filming.
The sound for a given frame is recorded 18 frames
before. This means that, for editing purposes, you
should continue filming one or two additional
seconds before and after each cut so that filming
duration matches the sound track to be recorded.
This is especially important when filming conversa­
tions, explanations and announcements where im­
portant parts cannot be cut. For editing, please use
a regular 8mm sound film editor and make sure to
monitor the sound while editing to avoid cutting
out necessary parts of the film.
* If you don't wish to film and record simultaneous­
ly while using a sound film cartridge, the micro­
phone must be disconnected.
Filming