Sound for Silent 8mm film

[jerrysch]

I have an S8 reel of a Bugs Bunny cartoon. I recorded on tape, the sound track from a VHS version of the same cartoon. When I play the cartoon, I run the tape as well, but the audio keeps getting ahead of the film. Why does it do this and what can I do to remedy this?

Jerry

[jessh]

Sounds like either they sped it up a bit for video or the projector is just running a bit slower than the video, either way the projector is not going to maintain an exact speed, neither will an analog tape recorder. There are two things I can think of that you can try for double system projection, one is to get a fancy double sysem sync sound setup (read lots of $$$ or lots of work), or you can get a tape player with a variable speed control of some sort and ride the speed control to keep it in sync.

~Jess

[wahiba]

Human beings are very tolerant of poor presentation. Hence, many old films filmed at 24 fps are transmitted without change at 25 fps on TV and no one notices. Consequently your projector could be plus or minus 1 fps and probably varies during projection. If the sound is on a cassete tape this is probably the same, although CDs are probably more accurate.

Only with mechanical locking, ie a sound track on the film, or very sophisticated crystal controlled systems can synchronisation be achieved.

Even computer editing is not excempt. I recorded a programme off the TV onto VHS tape. So far so good. I then saved it onto the computer and the sound went out of synch. with the picture.

It would probably be cheaper to buy a DVD of the Bugs Bunny movie and a video projector than trying to synchronise your projector and tape player!

Unless, of course, someone knows different?

[Pedro]

The effort depends a lot of the existing equipment, projector and tape player.
Even if both devices are of high quality - only if both are running crystal accurate,
sync will be maintained without futher coupling. Crystal accurtate projectors do not exist,
but some can be enabled to run crystal accurate.
For coupling both devices, any mechanical coupling like in the 1960ies is totally outdated.
The technology since the 1970ies is digital coupling of sound and film.
The Elmo GS1200MO just comes with all electronics needed for digital coupling to sound.
The sound only must be recorded with one reference pulse per frame on a sync track in parallel to the sound.
For Bauer studio class and Braun visacustic, external synchronizers can control the projector´s speed according to
the sync track of the sound. Projectors which are not controllable (like the Elmo ST1200 models) may have internal reed contact,
which provide a reference signal for controlling the speed of the tape. This requires special/modified tape players and
synchronizers.
In the case of the Elmo GS1200, things are quite simple: connect it to a crystal generator, set to 25 fps for PAL dubbing.
Now it will run exactly in sync with the sound from video tape, DVD or CD (NOT MC!!!)
Pedro

[jerrysch]

Well, I have some Popeye reels that come with a record (it's called "Sound Movies For Your Silent Projector"). I transfered the audio on the record to a tape and it syncs up just fine. The audio is slow. I think it's because 8mm runs slower than other formats.

Jerry