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Author Topic: Why is my movie scratched? Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 03-09-2004 01:24 PM                     I really enjoyed APOLLO 13 in IMAX but the sound and image were noticeably out of sync throughout. None of the other IMAX movies had any real "lip-sync" footage so it's hard to tell if that was ever an issue with those presentations. Most IMAX presentations I have seen were technically very good. My major complaint with IMAX was centred on the movies themselves and the high admission cost. With the rising cost of admission to 35mm presentations and the hit-or-miss quality available at the standard multiplex, I tend to wait for DVD's for most of the general releases. "Harry Potter," "Catwoman" and "The Matrix" are not movies that I would typically patronize theatrically so releasing them in IMAX doesn't do much in the way of attracting my business. Still, if given a choice between seeing a movie I cared about at a multiplex (in 35mm) or at an IMAX venue, I would probably opt for the IMAX show. Having said that, it would also depend somewhat on the multiplex in question and how much/little I knew of the place. It would also depend on the distance to the nearest IMAX theatre offering the movie.  |  IP: Logged Brian Michael Weidemann Expert cat molester Posts: 944 From: Costa Mesa, CA United States Registered: Feb 2004 posted 03-09-2004 08:28 PM                        Any out-of-sync situation would be completely operator oriented. Since the film has no sound information on it at all (unmarried), the sound system is synched to a start frame. Once it's running, synched or not, it will stay that way the whole show, as there's no way to fix it after the fact. But synching up at the beginning is not hard to fudge ... if you know what you're doing. I'm glad Warner Bros. is taking advantage of the format, but DMR (while incredibly better than 35mm) is not as crisp as anything actually shot in IMAX. And we have no control over ticket prices, but I think it's more worth it to see a 2.5 hour film than a 45-minute one. But then again, I've seen Matrix Reloaded and Revolutions well over 100 times each (don't even ask about Lion King!) and I, personally, lose my ability to judge whether or not I'd pay for them.  |  IP: Logged Phil Hill I love my cootie bug Posts: 7595 From: Hollywood, CA USA Registered: Mar 2000 posted 03-09-2004 10:05 PM                  quote: ...I have not seen any IMAX presentations in probably a decade that I would call pristine at any location I've been to. quote: ...most museums and non multiplex large format houses blow the comercial ones out of the water for presentation standards. I totally agree with Brad and Gordon. I've been to many IMAX presentations all over the world in the last 15 years and by far the worst were commercial venues in Los Angeles and Las Vegas. BTW: The sound systems sucked too. quote: ...with the minimal wear involved with the "rolling loop"... That certainly isn't true. The conventional Geneva is much gentler to film. The deceleration cam/claw of the rolling loop is the primary reason for the extreme stress. quote: ...run must have had 3000 passes... That certainly is impressive for a rolling-loop projector. However in special venue 870 using conventional Geneva projection, 15,000 passes is not unusual. The film must be replaced due color fading from the lamp UV rather than from mechanical failure or scratching. >>> Phil  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 03-10-2004 08:45 AM                        quote: ...15,000 passes is not unusual. The film must be replaced due color fading from the lamp UV rather than from mechanical failure or scratching. I have samples of a 70mm 5-perf Kodak ESTAR base color print that was run 60,310 passes at one of the special venue theme parks. None the worse for wear other than slight scuffing of the edges and perforation area, and slight fading from over 60,000 exposures to the UV from the xenon lamp. "Film Done Right".  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 03-10-2004 12:34 PM                     Brian said "Any out-of-sync situation would be completely operator oriented. Since the film has no sound information on it at all (unmarried), the sound system is synched to a start frame. Once it's running, synched or not, it will stay that way the whole show, as there's no way to fix it after the fact. But synching up at the beginning is not hard to fudge ... if you know what you're doing" Not correct there can be sync drift caused either by a issue with the timecode generator or in the case of the DDP it sometimes does it on its own In most cases the MagnaTech is always spot on If the timecode generator is a JSK box it can be jogged while running to catch up or retard Phil said"That certainly isn't true. The conventional Geneva is much gentler to film. The deceleration cam/claw of the rolling loop is the primary reason for the extreme stress" The rolling loop is far more gentle and if the cam is set correctly it causes little stress. Yet to see a working 15perf geneva (saw the Vic8 on it's side and we all know how well tat ran )  |  IP: Logged Brian Michael Weidemann Expert cat molester Posts: 944 From: Costa Mesa, CA United States Registered: Feb 2004 posted 03-10-2004 04:29 PM                        Maybe on traditional timecode systems it would drift. (I haven't worked with any before.) As I understand it, the IMAX projector is hardwired to send a pulse to the main console eight times every turn of the rotor (it's an eight-gap rotor, so basically once-a-frame). The pulse marks a frame count that the DTAC sound system constantly references, so it synchs up to a frame count, not necessarily an external timecode. We've had sound issues where the computer hard drive skips or gets stuck; but at that point we just stop and restart the DTAC (while the projector itself is still running) and it gets back on track with the frame count. I used to work with the DDP system. It never drifted on me, though. I do kind of wish the system could be jogged forward or backward to keep up, while running, should a show be started off synch. I guess they designed it to discipline the operator to be perfect every time, which I believe is ultimately more important.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 03-11-2004 11:07 AM                     The normal tach speed is 10 pulse per frame in quadrature so it would be 24o pulses per second in quadrature yeilding a tach clock of 960Hz and from what I remember the standard Spice nutmeg and garlic reads standard tach info or maybe that has changed  |  IP: Logged Paul Konen Jedi Master Film Handler Posts: 981 From: Frisco, TX. (North of Dallas) Registered: Jun 99 posted 06-22-2004 09:49 AM                     Looking to the experts for some assistance. Equipment: Christie Package P35GPS Head, AW3 Platter, SLC Lamphouses Either CAT-701 or DTS Penthouse readers Anyway, one of my prints received the following scratch. (Look at second frame, across her forehead.) This tick mark repeats itself approx every 12 frames, and each successive tick shows up one sprocket farther down the image. What you can't see are the tiny scratches that are only on the right half of the image. They seem to have a definate boundary. Is doesn't exceed mid frame on the left, or continue to the right edge of frame. I've been thinking that it happened when, gasp, someone turned the ultramittent knob to the north pole position. But then, how can the angle of the scratch be so shallow. Thanks for your help  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 06-22-2004 11:27 AM                        It sure looks like a "platter scratch" or scratch from the film riding up on a large diameter roller flange. Does the scratch repeat exactly 16 frames plus one perf, or just close to it?  |  IP: Logged Paul Konen Jedi Master Film Handler Posts: 981 From: Frisco, TX. (North of Dallas) Registered: Jun 99 posted 06-22-2004 03:59 PM                     John, it was pretty on to being 12 frames plus 1 perf. A platter scratch would have been on the other side unless one of my operators did something wrong by putting a twist in the film path somewhere or coming off the Christie Take up assy. Thanks  |  IP: Logged Jason Burroughs Jedi Master Film Handler Posts: 654 From: Allen, TX Registered: Jun 99 posted 06-22-2004 04:49 PM                     I'm thinking that the film wasn't properly in a roller somewhere. The visable scratch comming from a burr or something like that on the flange of the roller. Plus could explain the other non-visable scratches you describe. Sounds lik the film was pinched between the flange of the roller and the keeper, instead of seated on the roller properly. I'm guessing probably the roller under the projector, as it would take a fair ammount of pressure to create the green/yellow scratch seen.  |  IP: Logged David Favel Jedi Master Film Handler Posts: 764 From: Ashburton, New Zealand Registered: Feb 2002 posted 06-22-2004 08:34 PM                     Same sort of scratch happened to me from the take-up arm roller  |  IP: Logged

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