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Author Topic: Weird shadows on the edge of frame Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 05-29-2006 07:19 PM                     quote: Dan Chilton No turret. One auditorium. No masking. Also no theater.... I drove to Springfield and could not find the theater!!!, or the problem!!  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 05-29-2006 10:55 PM                     Sorry...didn't mean any harm then...  |  IP: Logged Glen Rich Film Handler Posts: 55 From: Nedlands, Western Australia Registered: Feb 2002 posted 05-30-2006 02:58 AM                     Can't say I actually know this kid, Chilton, but I have been reading his blog on setting up and running his and his wifes small cinema. Got the following from their web page, Springfield's Premiere Independent Cinema • 408 W. Walnut, Springfield, MO 65806 • 417.429.0800 http://www.moxiecinema.com/ I'd check the lamp focus. Go to the manual for your lamp house, if you haven't got one you may well find it in the manuals supplied here, it will show you where the focus and lateral adjustment(horizontal/vertical), knobs/screws are. Take your time, it's one of those jobs you can do in a few minutes with practice. Be patient...  |  IP: Logged David Ingalsbe Film Handler Posts: 31 From: Eagan, MN, USA Registered: May 2004 posted 05-30-2006 03:52 AM                     of coarse I think we missed something he said when he moved the ap plate the shadow moved with it so i would check for dirt fuzz or random crap stuck to it. or it may have been really heated up and re-aniled.(sp?) or if i miss read the thread and missed something please excuse my own dumbness  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 05-30-2006 06:42 AM                     quote: Also no theater.... I drove to Springfield and could not find the theater!!!, or the problem!! My bad, I was in Illinois.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-30-2006 07:35 AM                     quote: Jason Miller could the ap plate have annealed? FWIW: Yes, the brass could have annealed if the lamphouse you are using gets the brass hot enough to do so. That much heat typically comes from 3kw and higher lamp wattages though or from an improperly operating lamphouse without adaquate heat filtering(like missing hot mirrors). When the brass anneals it generally shrinks just very slightly but always all the way around... not just on one side. I've had many a high power lamp/projector that I filed the plates very tightly for only to have to go back and touch them up a month or more later. Your problem looks to me like the projector has tilted up just slightly and you're seeing the bottom edge of the plate. Keep in mind that all buildings expand and contract with changes in the seasons and a slight re-aiming of the projector may be necessary. I see this all the time on systems with very tightly filed plates. Also lens mounts are not always that repeatably accurate... like old Simplex's with the stretching lens mounts that can no longer be tightened properly, or Simplex's with TU-2000 turretts and the dam nylon stopper screws that change dimension every time you close the turret. At new locations that have that dam carpeted booth syndrome the projectors slowly sink into the carpet and also require re-aiming. Just some thoughts you can easily check out..... Mark  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 05-30-2006 08:45 AM                     I've never seen an aperture plate get smaller unless someone peened the edges which would be quite obvious. I've seen this phenomenon before, and it turned out to be a loosened rear lens element. The picture was focusable but smaller, like a zoom effect. You might check that the rear element retaining ring is screwed in all the way.  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 05-30-2006 09:14 AM                     Possibly a Magnacom?  |  IP: Logged Dan Chilton Expert Film Handler Posts: 191 From: Springfield, MO Registered: Mar 2004 posted 05-30-2006 11:59 AM                        I think Mark Gulbrandsen hit it on the head - the projector has been tilted up by just the smallest amount as the building continues to settle in the heat. We're in a very old building with a concrete slab foundation. Our auditorium has a 10" slope from the back to the front that was not planned... that's just the way our old building has settled. I'm going to file the plates back a bit and go from there. As always, thanks for all your help guys! And yes, we're in Springfield, MISSOURI, not ILLINOIS... or MASSACHUSETTS.  |  IP: Logged Rick Raskin Phenomenal Film Handler Posts: 1100 From: Manassas Virginia Registered: Jan 2003 posted 05-30-2006 03:49 PM                     Why not just adjust the projector tilt instead?  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 05-30-2006 04:33 PM                     quote: Rick Raskin Why not just adjust the projector tilt instead? Because that could effect the weight distribution of an unstable building. Also if you tilt it, which way? The shadows appear on the top and bottom. Maybe the building is shrinking? Also , be prepared to buy new plates when the building gets cool again This is quite the conundrum!  |  IP: Logged Dan Chilton Expert Film Handler Posts: 191 From: Springfield, MO Registered: Mar 2004 posted 05-30-2006 06:23 PM                        quote: This is quite the conundrum! I told you so.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-30-2006 08:21 PM                     Again, I see this all the time in older theaters. Generally some aperature plate size can be reached that works for hot and cold seasons providing that you have good quality masking to spill over onto. People rarely notice the spill over onto the black masking as their attention is normally focused on the moving image thay paid to see. So in your case touching up the plate would probably be appropriate thing to do but I would still run a target loop to be sure the projector is aligned to the screen properly before filing any plates out. quote: Richard Hamilton Because that could effect the weight distribution of an unstable building. Thats an odd thought. Most of the very old theaters that I service are built alot better than almost any of the new construction being done today..... Its the new construction in which I would be seriously concerned about weight distribution. Light weight steel truss joists are just no substitute for a large set of old iron I-beams. Many of todays booth floors have condsiderable bounce to them after being loaded with all the booth gear. Mark  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 05-31-2006 06:43 AM                     Dan, I don't have anything scheduled for the rest of this week. If you are willing to cover my travel expenses, I could come over and look at the problem. I am 250 miles away, so it would cost you about 100 to 150 bucks(my car guzzles gas!) Rick  |  IP: Logged

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