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Author Topic: scratches (in middle?) Chad Smith Film Handler Posts: 13 From: Lafayette, IN, USA Registered: Jan 2004 posted 08-26-2006 02:55 AM                     NOTE: I believe that the scratches set closer to the soundtrack. I will have an actual picture of the film up sometime later today. I just drew this to hopefully assist in the understanding of my situation for the time being. Christie P35GPS, potts platters, flim sits soundtrack up. Scratches are on the emulsion side. To describe the scratches in words: marks in the approx. middle of the film that bunch together to form what looks like a very elongated sine wave on the soundtrack side of the scratch and that have a varying length, yet remain in what seems to be the center vicinity of the film. If I recall correctly the scratches taper towards the foot of the frame and curve slighty, which was hard to represent in my mspaint drawing . The frequency is constant throughout the film and tapers near the end of the flim (I will post a picture of the taper later today with the scratch picture). The taper that I speak of trails off downwards (away from the soundtrack) and the marks get smaller and smaller and eventually disappear. This taper happens approx. 15-20 feet before the end of the feature. If you need anymore information just let me know. I'll come back around with ACTUAL PICTURES of the scratches later today Thanks for being awesome!  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 08-26-2006 03:46 AM                     Looks like you got a roller that is in contact with the print on the emulsion side - and with some serious film tension going across the roller...are your return rollers on the POTT's showing any hints of pressing on the emulsion side, since this roller is the last roller that there is film contact with before it goes into the main wind on rewind. Also, if the last few minutes, wonder if your rewind is drastically more tighter than normal, causing the film to actually buckle into the roller itself. ..some ideas to check into ... - Monte  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 08-26-2006 03:47 PM                        Emulsion side scratches are sometimes due to loose tension around the sound drum, esp in Century projectors; may apply to Christie as well. Same thing for Dolby Digital penthouses, too. In a projector, NOTHING else typically touches the emulsion side. As always, make a loop of new soft emulsion film, and thread as much of the film path as you can and leave alone for 10 minutes.Then reverse the sides so that the emulsion is on the base side and run again. If no problems then THAT MUCH is OK. Louis  |  IP: Logged Bill Enos Film God Posts: 2081 From: Richmond, Virginia, USA Registered: Apr 2000 posted 08-26-2006 05:46 PM                     Film winding onto the platter deck laying flat and touching the edge of the deck instead of being vertical and touching the film edge only.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 08-26-2006 11:24 PM                     quote: Louis Bornwasser Emulsion side scratches are sometimes due to loose tension around the sound drum, esp in Century projectors; may apply to Christie as well. Same thing for Dolby Digital penthouses, too. Two points here. #1 So long as the bearings are good in the sounddrum, no this is not possible. Sure it would take noticeably longer for the sounddrum to get up to speed (maybe 20 seconds instead of 5), but the fact remains the sounddrum WOULD spin and not cause any damage. #2 The scratches depicted in the drawing above are horizontal, which means it couldn't have possibly happened at the sounddrum. Plus it would've most probably affected the entire width of the picture. What I originally thought happened was the film was dragging severely across a roller flange. The only problem with this theory is that the scratches taper off as the film progresses, meaning this HAD to have happened at the final roller in the takeup on the platter. What vintage Potts platters are these? Now if the scratches were vertical, but otherwise in roughly the same position, I would blame a lower loop being threaded too large in the Christie projector.  |  IP: Logged Dan Lyons Jedi Master Film Handler Posts: 698 From: Seal Beach, CA Registered: Sep 2002 posted 08-27-2006 03:56 AM                     quote: Emulsion side scratches are sometimes due to loose tension around the sound drum, esp in Century projectors; I think you mean BASE side, as that is the side that comes in contact with the sound drum. Simplex's can scratch though, if the bearings in the dirt embedder roller freeze up.  |  IP: Logged Bruce Hansen Jedi Master Film Handler Posts: 847 From: Stone Mountain, GA, USA Registered: Dec 1999 posted 08-27-2006 09:21 AM                     If the scratches are at a slight angle (as some are in your drawing) they may be caused by a roller being too low, and allowing the film to scrape on the edge of the platter on take-up.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 08-27-2006 09:56 AM                        Brad/Dan: I became confuzzled while writing. You are correct. Louis  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 08-27-2006 01:05 PM                     When I see horizontal scratchs I look closly to see if they are angled with a curve and the angle changes during the course of a print or is the angle constant If it is constant then it can't be from rubbing on the edge of the platter since that angle changes as the roll on the platter grows If it is constant then it is almost always from the film sitting on the flange of a roller from improper threading or caught between a keeper roller and a roller again from careless threading  |  IP: Logged Kevin Raisler Film Handler Posts: 52 From: Warsaw, IN, USA Registered: Jun 2003 posted 08-27-2006 11:41 PM                    I disagree. scratches like that CAN occur at the sound drum by a roller in the traverse which runs full contact on the emulsion side of the film. (like a 5 star sound head) The idea here is how clean is your booth floor. If there is anything sharp that the tail picks up and then drags into the sound drum next show, which becomes embedded into the roller, then trashes the print in subsequent screenings..  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 08-28-2006 12:06 AM                     Kevin, that's exactly what Dan Lyons just said. However the projector in question is a Christie, and there is no such stupid roller in that projector's design.  |  IP: Logged Kevin Raisler Film Handler Posts: 52 From: Warsaw, IN, USA Registered: Jun 2003 posted 08-28-2006 12:26 AM                    I'm not firmiliar with christies.. I apologize for the confusion..  |  IP: Logged Chad Smith Film Handler Posts: 13 From: Lafayette, IN, USA Registered: Jan 2004 posted 08-28-2006 06:27 AM                     Alright, I don't want to rule anything out yet but I do want to provide some more information. Scratches like these have occured for us four, maybe five times in the past year if I recall correctly, but completely randomly and on different projectors(!). We have never had scratches like these on our dolby houses, only on our DTS houses, which could just be by chance (we have 3 Dolby houses and 5 DTS houses). I have two examples of the scratches we get that I have collected so far. Sadly, I do not have a photo of the scratch I depicted above yet, but hopefully I can get that today. In the meantime however, here is the only other example I have right now. I believe that all of the scratches are related somehow, seeing as how in the three years that I've been there, excluding these scratches, there have only been two prints scratched and they have been due to user error. Here are a couple more pictures that can hopefully be helpful (all of our projectors are setup in this manner, the only difference being DTS/Dolby):  |  IP: Logged Neil Fish Film Handler Posts: 16 From: Norwalk, Ct Registered: Dec 2000 posted 08-28-2006 04:04 PM                        The first set of scratches illustrated are typically caused by a too-large lower loop on the Chrisite projector. Often, the loop starts out on the large side of correct, but if the operator had to frame down (up on screen), the loop would grow, and slap on the underside of the shutter housing. The second set is almost certainly from the film loading onto the platter from a too-low angle, either from the makeup table or a mis-adjusted roller.  |  IP: Logged Bruce Hansen Jedi Master Film Handler Posts: 847 From: Stone Mountain, GA, USA Registered: Dec 1999 posted 08-28-2006 06:46 PM                     quote: Chad Smith and the marks get smaller and smaller and eventually disappear. This taper happens approx. 15-20 feet before the end of the feature. If these are platter scratches that could explain there being no scratches on the last 15-20 feet of film. After the tail leaves the last sproket in the projector, the last 15-20 feet of film is no longer under tension as it winds onto the take-up platter, and would not get scratched as easily.  |  IP: Logged

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