8mm Forum: Optical Sound Question /w/ Elmo ST1200 Series machine

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Posted by Chip Gelmini (Member # 44) on October 14, 2005, 12:09 PM:

I am curious if faded optical sound prints might have impact on threading via autoload. I've adjusted head pressure with the tension spring behind the optical bulb. The sound when it plays, goes between good sound with nice treble, to bad wobble sound with low treble.

Upon examining in play mode, there's quite some slack around the optical assembly as the film runs.

This has nothing to do with my Towers, as I have checked these machines with the machine arms holding the reels.

As it happened recently, I simply used my finger and pulled down the bottom loop to make it bigger by one or two sprockets. and this seemed to have quite a better difference.

This problem has been noted on both machines I use, therefore, I suspect print quality being the issue.

It is also noted that magnetic sound film autoloads and plays just fine. These machines do have a mechanical difference between mag and optical sound, that being in optical mode the mag head pressure is reduced.

Any information is greatly appreciated to this. While I use the 1200HD units, those who run optical with the GS1200 might want to pay attention to this as well. Let's see if there's a connection.

In the next few days I'll run one of my better color optical prints. And maybe that will help me figure this out.

CG

Posted by Osi Osgood (Member # 424) on October 14, 2005, 03:17 PM:

I wish I could give some valid good advice on that optical sound. I don't have a GS1200HD, so I couldn't judge how it works personally. Every once in awhile I'll run into a problem with a print aparrently loading wrong and getting that "wobble" to the sound. It's certianly not with the print.

I wouldn't think that the color fade of a print would affect the sound much or any as it's an optic or light sensitive sound system. perhaps if the print was highly faded, (from straight black to a high reddish/pink) perhaps it could, but I've never ran into that.

Posted by Tom Photiou (Member # 130) on October 14, 2005, 04:10 PM:

Cant see a print with fade being any different to a normal colur print as far as running it thru a projector is concerned.
Fade is purely the lose of colour and nothing else, [Wink]

Posted by Kevin Faulkner (Member # 6) on October 15, 2005, 09:37 AM:

Chip it sounds like the sort of problem you get when the pinch roller etc gets shiny. You get less grip on the film.

Film fade wont be causing problems unles the sound overall is very very low but it wouldnt tend to vary.

Kev.

[ October 15, 2005, 10:50 AM: Message edited by: Kevin Faulkner ]

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