This is topic STAR WARS II - Picture movement on screen in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Jamie Sanson (Member # 1161) on 05-23-2002, 03:44 AM:
Since we have commenced screening Star Wars II, the picture moves vertically up and down throughout the feature intermittently. I have checked all the usual "suspects", such as gate, gate runners, gate tension and intermit sprocket. At first I thought it was the projector, but can find no fault so I believe it must be the print. The projector is a VIC 8.
Posted by John Wilson (Member # 269) on 05-23-2002, 06:18 AM:
Hi Jamie and welcome aboardAre your ads and trailers doing the jump thing also?
There are scenes in SW that move around and yet others that are steady as a rock.
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"It's not the years honey, it's the mileage". - Indiana Jones.
Posted by Ron Lacheur (Member # 1126) on 05-23-2002, 11:46 AM:
We have all Vic 8's at my work, and Ep2 is running A+ on all of them. But I have noticed on the ending credits on all features seem to shake a bit vertically.
Posted by Bobby Henderson (Member # 840) on 05-23-2002, 06:02 PM:
Obi Wan's eye floats up and down on his face in one scene. I mentioned this in another post though.
Posted by Manny Knowles (Member # 1171) on 05-23-2002, 06:13 PM:
Ron: For what it's worth, I have noticed a small, yet discernible amount of "jump" (vertical instability) during tail credits on every projector I have ever worked with.Tail credits reveal this problem moreso than actual footage because the movement of credits is uniform and predictable. Obviously, static credits (aka "title cards") would reveal this even more. The point is that you may not really have a problem.
In order to rule out the existence of a mechanical fault, you'd first need to measure the severity of the jump in your projector. Among its many uses, the SMPTE 35-PA (aka RP-40) test film is designed to help determine if your projector is within the specified tolerance limit for jump (and also "weave" which is the side-to-side equivalent).
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~Manny.
Now...where was I ?
Leonard Shelby, MEMENTO.
Posted by Jamie Sanson (Member # 1161) on 05-24-2002, 03:48 AM:
Thanks guys for the feedback on SW. The projector is rock steady on other prints. I have notified FOX Film Distributors and are aware of other problems at various locations around the same copy number as 146.
Posted by Pete Naples (Member # 761) on 05-24-2002, 11:15 AM:
I'm sure I read something about this before, I think John P. posted some links about it (surprisingly!), basically most end credits are printed at very high speed, and the results can sometimes be less than stable.
Posted by John Pytlak (Member # 331) on 05-24-2002, 12:31 PM:
One possible source of vertical unsteadiness is the common practice of using a continous contact printer to print a short pitch original to a short pitch raw stock, such that there is slippage in the printer gate. Continuous contact printers require a short pitch original and a long pitch raw stock for optimum steadiness. Otherwise, a pin-registered step printer should be used, such as for printing a long-pitch master positive to a short-pitch duplicate negative:
http://www.kodak.com/US/en/motion/support/h1/sizesP.shtml#perfs On some continous contact printers, improper adjustment of the tensioning of the film as it goes over the printing sprocket can cause intermittent vertical unsteadiness.
One quick, sure way to tell if the unsteadiness is from your projector is to pull the aperture plate, and project the edges of the print's perforations. If the print perfs are "rock steady" and the image is moving around, the unsteadiness was printed in.
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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
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