Film-Tech Forum ARCHIVE: variable density prints

This is topic variable density prints in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Joseph Matteo (Member # 4096) on 05-04-2011, 08:48 PM:

Has anyone had any experience with this sound format using red led.Last week i received a sos the projectionist tried to play treasure island that had a variable density track.The projector was a Norelco AA 35/70 all other films played fine but the treasure island was completely silent.the film was cancelled.

Posted by Mitchell Dvoskin (Member # 751) on 05-04-2011, 09:58 PM:

I've never had a problem with variable density tracks on red led readers. They should play just fine, unless the density track itself is magenta.

Posted by Steve Guttag (Member # 268) on 05-05-2011, 06:40 AM:

Many density tracks are indeed magenta. I have run into this problem as well.

If they are B&W then they should play fine (presuming they got their density correct...and many don't).

Posted by Gordon McLeod (Member # 33) on 05-05-2011, 11:19 AM:

I have never had an issue with variable density and red readers wich treasure island is it was it the disney (IB tech so it would have a silver track) or the black and white one

Posted by Kirk Futrell (Member # 5006) on 05-05-2011, 12:26 PM:

What sort of processor was it running through? Or would that not matter (seems like it would)? I've never had problems on Dolby systems.

Posted by Stephen Furley (Member # 1277) on 05-05-2011, 12:44 PM:

quote: Kirk Futrell
What sort of processor was it running through? Or would that not matter (seems like it would)? I've never had problems on Dolby systems.

It shouldn't make any difference. It's the variation in the amount of light falling on the cell which generates the signal. Whether that variation was caused by changes in optical density or in width of the track doesn't matter; varying amount of light generates varying electrical signal and at the point where this is fed into the optical pre-amp in the processor it makes no difference.

Posted by Kirk Futrell (Member # 5006) on 05-05-2011, 01:03 PM:

So much basic stuff for me still to learn... Thanks.