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Author Topic: Half of screen in focus, other half not + bouncing Richard Greco Phenomenal Film Handler Posts: 1180 From: Plant City, FL Registered: Nov 2003 posted 03-22-2004 09:49 PM                     Ok, lemme make this short and sweet.... a little tired. Running a Century SA projector Drive-In (Lp-270) platters Film: Agent Cody Banks 2 Problem: During the movie, I notice a LOT of bouncing on screen. I never had that problem b4 so what can I do to check it. I am not a tech or trained as one. I never have been inside a lamphouse b4 either. (Only been working as a projectionist for 6 months) Part 2: During the white on black part of the credits, I notice as the words are scrolling upwards that the bottom of the screen is focused and the top is not. It actually looks like the words shadow themselves. It is VERY noticable and is unreadable at the top of the screen. I cleaned the lens and port window. I cleaned the projector as well. I also tried adjusting the shutter knob for the possible travel ghosting. The projector makes sort of a grinding noise if I turn the knob a specific way. Any Ideas? It is impossible to read the credits at the top of the screen. However I don't see any issues during the film. Part 3: Also, this film is in a theatre that has the screen skinnier than the others and doesnt have any movable masking. ALL scope films played in that auditorium have a large piece of the picture showing on the left side of the wall. Could that be needing a new plate cut? Thanks.  |  IP: Logged Ron Lacheur Jedi Master Film Handler Posts: 650 From: British Columbia, Canada Registered: Feb 2002 posted 03-22-2004 10:29 PM                     The picture is bouncing on the screen? You might want to check your gate tension.  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 03-22-2004 10:42 PM                     No offence intended... First thing you should check is how clean the projector gate is. Dirt build-up in the gate and associated parts can cause the projector to become unsteady. Once that's out of the way, turn the gate tension knob all the way counter-clockwise. Then slowly turn it clockwise until you get the steadiest picture possible. Hint: You shouln't need to use much tension at all. It should certainly be less than half way. More like 1/3 or even 1/4. Use the lowest tension setting possible. If that doesn't work then you'll need to look at other things. Probably something you should ask your technician about. As to the picture looking out of focus: Sounds like your shutter is out of time. Does it look like the picture is made of wet paint smearing down the screen? That's shutter timing. It's not hard to fix but you will need to take tools to the projector. It'll literally take you 5 minutes to fix it. (Or even less.) How sketchy are you about that? More importantly, how sketchy is your manager about that? And, finally, Yes. The aperture plate is suspect. It may simply not be inserted the right way. It may need to be replaced/recut but the thing you should look for first is to see if the apreture plates haven't become swapped between projectors.  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 03-23-2004 04:14 AM                        Stuck or too loose lateral guide roller.  |  IP: Logged Richard Greco Phenomenal Film Handler Posts: 1180 From: Plant City, FL Registered: Nov 2003 posted 03-23-2004 06:37 AM                     Randy, Please explain what a gate tension knob is. Yes it sort of looks like running paint ONLY at the top of the screen. I tried turning the shutter knob but it makes a LOUD noise when I start turning it. Michael, WQhat is a lateral guide roller? Is that a roller inside the gate?  |  IP: Logged Rick Long Jr Expert Film Handler Posts: 211 From: Toronto, Canada Registered: Jul 2000 posted 03-23-2004 07:12 AM                     Defifitely sounds like shutter timing. But it shouldn't make noise when you turn the shutter knob. If you've never done it before, I'd respectfully suggest you call in a tech to figure out what's making the noise. In my experience a grinding noise from a projector head is a BAD thing if left too long. On an SA, the gate tension adjustment is at the top of the gate. a little knob with a line on it. Personally, every SA I've ever worked on runs perfect at the MINIMUM tension(knob counter-clockwise) The lateral guide roller is in behind the pressure bands at the top of the trap. the outboard flange is fixed, but the inner one is spring loaded to keep the film up against the outer edge of the trap. check to make sure it's clean and free. use the end of a toothbrush or something to push on the inner flange. It should push away from you, and come back freely.  |  IP: Logged Mitchell Dvoskin Phenomenal Film Handler Posts: 1869 From: West Milford, NJ, USA Registered: Jan 2001 posted 03-23-2004 08:32 AM                     I agree that the smearing of the credits is a shutter timing issue, but overall "bouncing" could be bad film printing, especially if your pre-show material does not bounce. /Mitchell  |  IP: Logged Gary Crawford Expert Film Handler Posts: 200 From: Neptune NJ USA Registered: Nov 2003 posted 03-23-2004 01:22 PM                     If the credits are out of focus just at the top but not smearing, you may have to take that lens apart to clean the inner surfaces. If it is a scope lens, do it when you aren't running a show, and use a target test loop after you reassemble it. You may find your scope image is "crooked" or "sideways" and you'll have to turn the lens in its collar to correct that. If you never took a lens apart before, have your tech show you how to do it. I have 3-stage Kollmorgen scope lenses and the last time I took them apart, cleaned them and screwed the stages back together I noticed the image leaned to the left, so an easy readjustment right in the machine took care of that. Just do it before or after you have people in the auditorium or you'll get complaints that "the picture looks funny."  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 03-23-2004 01:35 PM                        Is this a new change, or has this machine always had this problem with all prints? It sounds like the problem is a combination of shutter timing (the ghosting) and something else (the picture not being centered on the screen). As for the latter, try running the same machine with a different lens and plate; if the picture is fine, then there is something wrong with the current lens and/or plate that you are using. Try removing the lens from the collar and re-seating it (you'll have to re-set the focus lock ring when you do this). Also make sure that there are no loose elements in the lens.  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 03-23-2004 09:10 PM                     A cracked lens could be responsible for the focus issue. The bounce may be due to a problem with the intermittent. As for the scope image, the projector may have gotten bumped out of position. Alternatively, the lens may have been bumped out of alignment. Are you using a lens turret?  |  IP: Logged Richard Greco Phenomenal Film Handler Posts: 1180 From: Plant City, FL Registered: Nov 2003 posted 03-23-2004 11:13 PM                     Problem fixed with the bouncing & credits. Problem: One of the metal guides in the gate that hold tension snapped and the film wasn't tight enough. That killed two birds with one stone. The credits were perfect after that. As for the scope on the wall, Manny, What is a lens turret? This auditorium has a smaller screen than the others. It has no movable masking. I tried flipping the plate but that didn';t work. I don't want to get too technical b/c if my manager found me disassembling a lens, it would be my ass out to dry. I wanna try to keep it simple without going into the machine to where a tech is needed. Don't forget, I'm still a newbie so I don't know these things.  |  IP: Logged Chris Hipp Phenomenal Film Handler Posts: 1462 From: Mesquite, Tx (east of Dallas) Registered: Jul 2003 posted 03-23-2004 11:35 PM                     A lens turret is where you have two lense on a plate that spins around, or slides over into place. I believe your aperture plate has come up before. I would strongly suggest calling a techinician to check out all or your plates. Most likely they need to be recut, I wouldn't do that myself and wouldnt recommend it.  |  IP: Logged Floyd Justin Newton Jedi Master Film Handler Posts: 559 From: Phoenix, Arizona, USA Registered: Jun 2002 posted 03-25-2004 07:16 PM                     Richard-- I would suggest that you get the manuals on your equipment and read them COVER to COVER. Just about every question you'd ever have will be answered in them. fjn  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 03-29-2004 03:48 PM                        I agree, use the LEAST amount of gate tension needed to keep a steady image. Hopefully, you replaced the "snapped" gate band.  |  IP: Logged

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