Film-Tech Forum ARCHIVE: Optical Printer Question

This is topic Optical Printer Question in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Tim Reed (Member # 137) on 08-20-2000, 07:11 AM:

This may or may not be the proper forum for this question, but since I know there are some DPs that lurk here, maybe there are also people who have hands-on experience with optical work; so I am "fishing" a little.

Does anyone know how an optical printer with a "fixed-pin registration" pulls down? From what I've read, it sounds like the trap rails lift up and the film just slides by, then the rails retract. If true, then how does the film reliably remain in the focal plane from frame to frame? It would seem the film would bow or distort too much, lifting it in this manner.

Is there an intermittent sprocket?

Better yet, know where I can see a drawing of this movement? Thanks.

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Better Projection Pays!

Posted by John Pytlak (Member # 331) on 08-21-2000, 06:19 AM:

Kodak developed the "Liquid Gate for Optical Printing", using the normal "Bell and Howell" type movement usually used in optical printers. Several photos of the gate are in the paper by the inventor, Howard F. Ott, published in the April 1970 SMPTE Journal.

You are correct that the film is sandwiched between rails in a "trap" that lifts the film off the registration pins while the film is shuttled, then drops the film back onto the pins. These printers are typically run only a few frames per second, so there is plenty of time for the film to stabilize its position and focus.

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Tim Reed (Member # 137) on 08-21-2000, 09:18 AM:

Thanks, John! You're a big help!

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Better Projection Pays!

Posted by Chris Erwin (Member # 176) on 08-25-2000, 10:10 AM:

Tim,

I just ran into something that might go with your last post on your project with the sound. The Smart Mod IIB has an option that synthesizes stereo from mono soundtracks.

Just thought I'd pass that along.

--Chris
P.S. Forgive me for posting to this post vs. finding the old one and posting to that!

Posted by Tim Reed (Member # 137) on 08-26-2000, 10:01 AM:

Thanks Chris! Oscar's got me taken care of in the sound dept.

Tim

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Better Projection Pays!