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Author Topic: Scope focus not uniform Jessica Lois Phipps Film Handler Posts: 7 From: Durham, NC, USA Registered: May 2005 posted 06-02-2010 09:08 PM                     I did a search for scope focusing issues and didn't see anything specific to this problem. The gist of the issue is that while projecting in scope and the center of my image is in focus, the image toward the upper part of the screen is noticeably out of focus (maybe the top foot or two on the screen) and the bottom part of the screen is less noticeably out of focus. The right and left sides appear to be in focus with the center. Does this sound familiar to anyone? Any suggestions?  |  IP: Logged John Wilson Film God Posts: 5438 From: Sydney, Australia. Registered: Dec 1999 posted 06-02-2010 09:24 PM                     Hi Jessica. What sort of Projector head do you have? It would seem the lens is not at the same angle as the film going through the gate. That is...the top of the lens is closer to the print than the bottom of the lens (Or vice-versa) On some machines (Century) this is an easy fix. On others...not so much.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 06-02-2010 09:28 PM                     It is possible that the film is not sitting flat in the trap and the lens can't converge the entire frame also is there a steep projection angle  |  IP: Logged Jessica Lois Phipps Film Handler Posts: 7 From: Durham, NC, USA Registered: May 2005 posted 06-02-2010 10:17 PM                     Hello, friends! Thank you for the help. Lucky for us, it IS a Century. The lens says "264" and "Manufactured by Projection Optics Co" or some such, if that matters. I'm not sure why the film wouldn't be flat in the trap, but I'm new to troubleshooting image quality issues like this, so please feel free to entertain any idea you might have! Thanks again!  |  IP: Logged Danial Simmonds Expert Film Handler Posts: 107 From: Kota Damansara, Selangor, Malaysia Registered: Jan 2008 posted 06-02-2010 10:41 PM                        Just to share, I had experienced a lens that was partially burnt due to a projectionist aiming xenon light for a very long time directly to the lens, it caused part of the picture to be blurred and the rest focus and vice versa. But it was a Scope lens.. Regards Danial  |  IP: Logged John Wilson Film God Posts: 5438 From: Sydney, Australia. Registered: Dec 1999 posted 06-02-2010 10:54 PM                     quote: Gordon McLeod It is possible that the film is not sitting flat in the trap That'd be a more left/right focus issue. What model Century do you have? (See plate on front of machine) Also, do you have a lens turret on it or do you slide the lenses in manually?  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 06-02-2010 11:30 PM                        You probably have a loose element in your lens. If you can, remove the lens and gently shake it close to your ear. If you hear a slight rattle, it is likely time to replace the prime part of that lens.  |  IP: Logged Eric Robinson Jedi Master Film Handler Posts: 538 From: Santa Rosa, CA Registered: Jan 2005 posted 06-02-2010 11:48 PM                     There are so many factors which could be the problem. Instead of guessing, why not perform some deductive reasoning? For instance if there is another auditorium with similar throw and screen size, move the lens there and see if the problem follows. If so, its a lens problem, if not, its a projector or port window problem.  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 06-03-2010 12:45 AM                        You can trust Eric's advice. His face changes color, after all.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-03-2010 01:44 AM                     ..could have worn bands in the trap assembly, or a lateral guide roller at the top the trap catching the edge of the film which would tweak it... It could be an Automatic with the slider in front where the prime is the common lens and the flat is a Magnacom lens...  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-03-2010 11:05 AM                        If you have any variant of the "SA" Century, it is likely that the "studio guides" are set too close together causing film to buckle. This is a common error, promoted by the factory. In fact, the guides should not touch the film. Proper operation is expected even with them removed. btw: if you are still running ANYTHING made by Projection Optics, you are leaving serious brightness and quality behind when the light goes through the lens. louis  |  IP: Logged Jessica Lois Phipps Film Handler Posts: 7 From: Durham, NC, USA Registered: May 2005 posted 06-03-2010 12:57 PM                     I'll check out the projector model when I get to work tonight. I couldn't see it last night when I was posting because the film was running and the (very old, falling apart) manual didn't have a model number listed. I am 95% certain it was purchased in the 80s based on a date listed in the manual. Here's a picture, if that helps in the meantime: We slide the lens in manually, lining up a tab on the lens with a notch on the projector. I'll try shaking the lens when I get in tonight. If the issue were in the trap, wouldn't we also have a similar problem running flat films? The problem seems specific to scope films. We have two screens and I've avoided bringing the other lens in because the throws are different. I figured it would be less destructive to ask here first before I go messing with anything. Also, don't be hatin' on my lens. Its an inheritance from the previous owner. Not much I can do about that. Oh, and thanks again to everyone for helping out! [ 06-03-2010, 11:25 PM: Message edited by: Adam Martin ]  |  IP: Logged Mitchell Dvoskin Phenomenal Film Handler Posts: 1869 From: West Milford, NJ, USA Registered: Jan 2001 posted 06-03-2010 01:43 PM                     Your "scope" lens consists of two separate lenses screwed together. The lens toward the film gate is the "prime" lens, which is just a flat lens that enlarges the picture equally in all directions. The lens toward the screen is the anamorphic adapter that enlarges the picture twice as wide as it does high. Separate the two lenses by unscrewing them and just put the prime into the projector. If the problem persists, then the prime is probably your problem and needs to be replaced. If the problem goes away, then you have a bad anamorphic adapter, and it needs to be replaced. You can double check the prime by placing it in another projector. Those prism design "264" anamorphic lenses leave a lot too be desired. I have a few laying around the house that I use as paper weights. You would do better to buy a used ISCO anamorphic lens off of eBay, regardless of whether yours is defective or not.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 06-03-2010 02:39 PM                        You have a Century "C" projector with a straight gate.(Could be from 1941 up to about 1960. I would look first for a lens problem. Like the man says, seperate the front and the back scope lens to see if the back lens is OK. (Picture will be full height, but half as wide.) Louis  |  IP: Logged Jessica Lois Phipps Film Handler Posts: 7 From: Durham, NC, USA Registered: May 2005 posted 06-03-2010 06:38 PM                     The projector is actually an "SA" model - I think I may have accidentally posted a picture of our other projector, which is a "C". I never realized there was a difference between them until now, actually. From my perspective, they both seem pretty identical inside. Thank you for the play by play on how to separate the lens. I'll try this tomorrow during down time. You guys are the best!  |  IP: Logged

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