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Author Topic: Problem with Small Emulsion "Dot" Every 3 Frames Patrick Matthews Film Handler Posts: 86 From: Kansas City, MO, USA Registered: Sep 2004 posted 03-18-2005 02:00 PM                     I just got a new print in (not a brand new print, just a new one to our theatre) the other night and ran it for the first time and I noticed after the run that about every 3 frames on the soundtrack side of the film that there are tiny littly dots where the emulsion is scratched. There are not numerous ones on each frame, just one, and it gradually works its way down the frame every 3 frames. We are using a Ballantyne Pro 35 and a Potts platter. Any idea as to what would cause this and why it gradually works its way down the frame? It is really bugging the crap out of me!  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 03-18-2005 02:08 PM                     ..somebody built their their bottom loop too big coming out of the trap and gate assembly and the loop was smacking against an object underneath the intermittent assembly. A common thing with Christie P35GPS if the bottom loop gets built too big. They create these little "tik" scraches. Another possibility of platter rollers having a burr on the surface doing this "tik" scratch, or it was during a make/break session on the MUT. Why it's important to make the correct loop sizes on both top and bottom. -Monte  |  IP: Logged Patrick Matthews Film Handler Posts: 86 From: Kansas City, MO, USA Registered: Sep 2004 posted 03-18-2005 02:18 PM                     Hmmm...interesting because I made the loop the same size that I always do and I've never had this problem before. While I understand that it would damage the film if it was smacking something underneath there how would it create a dot that moved down the frame, wouldn't it be at the same place on the frame?  |  IP: Logged Jeremy Fuentes Mmmm, Dr. Pepper! Posts: 1168 From: Corpus Christi, TX United States Registered: Jan 2004 posted 03-18-2005 02:26 PM                     quote: Patrick Matthews I made the loop the same size that I always do maybe it was the theater before you, since it wasnt a new print.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 03-18-2005 02:32 PM                        Look for a roller that has a circumference of 3 (frames) x 0.1870 (perforation pitch) x 4 (perfs per frame) = 2.24 inches, or a diameter of about 2.24/Pi = 0.7 inches. I suspect that it may be a pad roller with a burr doing the damage.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 03-18-2005 02:45 PM                     On the pro35 check for damage on the roller that supports the lower loop under the intermitent if it has a burr on it it will cause damage like that also the guide rollers in the soundhead  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 03-18-2005 03:19 PM                     Get a virgin trailer and make a good sized loop out of it (such that you can properly drape it over rollers so it does NOT drag over the side/front/top of the projector when running) and let it run for awhile. See if the dots appear and get worse. If you don't see any marks, stop the machine and make the loops bigger and check that. You can rule out your projector pretty quickly that way. Loops slapping around don't always hit every single frame. Commonly they bounce up and down so that only every other or third/fourth frame hit.  |  IP: Logged Darryl Spicer Film God Posts: 3250 From: Lexington, KY, USA Registered: Dec 2000 posted 03-18-2005 07:00 PM                    quote: Gordon McLeod On the pro35 check for damage on the roller that supports the lower loop under the intermitent if it has a burr on it it will cause damage like that also the guide rollers in the soundhead Had an issue with that roller when I ran those machines years ago. Sometimes the roller wouldn't turn and it was wearing the roller down causing the film to want to buckle with the film picture area hitting the inside of the roller.  |  IP: Logged Patrick Matthews Film Handler Posts: 86 From: Kansas City, MO, USA Registered: Sep 2004 posted 03-18-2005 08:28 PM                     Ok, after watching another run of the film I noticed that this doesn't occur on every reel, but only reels 5-9. Question is, if indeed I did have it threaded wrong or it was something in the projector, like a burr, wouldn't it be on the whole print?  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 03-18-2005 08:45 PM                     Did you build onto large reels (1-4 and then 5-9), then platter?  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 03-18-2005 08:53 PM                        The plot thickens! But most likely a repeating "dig" is caused by a roller having the circumference equal to the spacing between the digs. Do you have an exact measurement of the distance between digs (more accurate than just saying three frames and the spot moves)? Then examine all rollers of that circumference to see if they have a rough spot that could scratch the film.  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 03-18-2005 10:51 PM                        To continue with Brad's thought--did the print come from a theatre that ran it on large reels with one changeover and misthreaded one machine? Were any/all of the leaders removed when it arrived?  |  IP: Logged Patrick Matthews Film Handler Posts: 86 From: Kansas City, MO, USA Registered: Sep 2004 posted 03-19-2005 12:59 AM                     Brad and Scott: No, I didn't build up on two reels, I went right from the shipping reels onto the platter. Also, the heads and the tails were all spliced back on, looks as if it was run on a platter before it got to me. As for the exact distance between them that is going to have to wait until i'm back in the theatre again but i'll be sure to post the distance when I figure it out.  |  IP: Logged

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