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Author Topic: Bad Focus Phil Blake Jedi Master Film Handler Posts: 558 From: esperance western australia Registered: Nov 2003 posted 01-17-2004 05:50 AM                        Hi all , having real focus issues down here in our cinema 3 , we have an intergrated anamorphic lens in the Vic 5 and it is not possible to obtain sharpe focus in cinemascope , widescreen is fine. The intergrated lens is a Schneider . I noticed 2 allen keys at the lens front one with focus and one with lock written on it. Has anyone had much to do with focusing these lens ? regards Phil  |  IP: Logged Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 01-17-2004 06:25 AM                        For anyone with direct experience with this lens, it would be helpful if you would indicate whether this is a new install or if that scope lens ever did work right. If it did, someone's either dropped it or they've made their own "field adjustment"... which also would be helpful to know.  |  IP: Logged Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 01-17-2004 09:31 AM                        Sorry if this sounds really obvious, but is it just a bad print? That having been said I once had a duff anamorph - I think it was an Isco, but can't remember - that made everything look soft as shite. We tried everything: screwing it into a different backing lens, adjusting everything there was to adjust but it just wouldn't give an acceptable picture. It was eventually replaced, which solved the problem.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 01-17-2004 09:45 AM                        Is the projection throw (distance from the projector to the screen) set correctly? If not, the lens will not focus horizontal and vertical detail at the same point (astigmatism). Here is the procedure: http://www.film-tech.com/tips/anamorphics.html  |  IP: Logged Kenneth Wuepper Phenomenal Film Handler Posts: 1026 From: Saginaw, MI, USA Registered: Feb 2002 posted 01-17-2004 03:55 PM                     A good test for proper alignment of focus and distance settings is to gently rock the focus knob while watching the screen. The image should "snap" in and out of focus over the entire screen. If you notice that the edges go soft first or the center goes soft first, you need to re-run the suggested alignment. My first experience with poorly aligned anamorphics was "PATTON" the opening scene with the huge flag and the blurry stars that I saw on the left side. That prompted me to discover for myself the process which is now so well described in the "Tips" section. Thanks to Film-Tech no others should have to re-invent this technique. KEN  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-17-2004 04:08 PM                     When properly set a target of verticle and horizontal lines will have the vertical lines go in and out of focus at the same rate as the horizontal ones  |  IP: Logged Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 01-17-2004 04:47 PM                        Well, with all due respect, it just seems that before he starts loosening lockscrews, the basic questions should be addressed. He hasn't said whether the lens was ever right in the first place, so suggesting he unlock the thing & start twisting the focus might be premature.  |  IP: Logged Matt Zeiner Expert Film Handler Posts: 146 From: Windsor, CT USA Registered: Sep 2003 posted 01-17-2004 06:18 PM                     umm...what real harm can be done anyways? I assume the lens is relatively new - the astigmatism would have to be off quite a large margin in this case. Why not look at the throw indicator and compare that with a rough measurement.  |  IP: Logged Chris Byrne Expert Film Handler Posts: 102 From: Kirwan, Australia Registered: Jan 2003 posted 01-17-2004 08:11 PM                     Hi Phil, You may have a loose element inside the backing lens. When removed from the turret, give the lens a gentle shake and see if you hear a rattle. If you are working on it for the first time, be very careful that you don't scratch the coating on the element. Also bear in mind that the throw setting on your anamorphic isn't always in agreeance with the 'actual throw' from projector to screen. If you haven't already got a loop of Target film (RP40), purchase a 10 foot loop from ATLAB. Do some surfing on this site for tips on what to look for in terms of optimum focus.  |  IP: Logged Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 01-17-2004 10:42 PM                        quote: umm...what real harm can be done anyways? Only that the suggestions above, while all good and valid when applied to a specific problem, are all over the place at present and are pretty much reacting to assumptions. You assume the lens is relatively new, but you don't know if it was working the day before this thread started. Therefore, the suggested fixes cover just about everything from initial alignment (which shouldn't need frequent repeating), to checking for loose elements (a good idea, but not what you might expect from a relatively new lens). Maybe the thing kissed a concrete floor from 5 or 6 feet, and then none of this matters. We just don't know yet. This board is full of these situations, where someone asks about sticking a screwdriver into something, only to be bombarded by well-intentioned suggestions, some overly technical and probably not recommended if the problem hasn't been identified first. Eventually, someone even thinks about asking if the poster has the experience, and maybe the authorization to be taking the screwdriver out of the tool box in the first place. So there's the reason for my caution, maybe even curiosity. You wouldn't want to go and twist the volume pots on your amplifiers because you sense a balance problem, only to find that the real culprit is something out of whack in your processor, yet this kind of thing happens all the time and you wind up with a bigger problem than what you started with. Again, with all due respect, if one of my people called to tell me the scope lens wouldn't focus, my suggestion that they start twisting the adjustments would most likely not be part of that phone call. But then, I would have gone into the call knowing what I had, how long it had been there, and the fact that those lenses had worked just fine up until some time very near when the call came in... all elements of the troubleshooting process that have not been established in this particular situation. Initially, given I'm not blessed with knob-tweakers, finding out that some staff member had decided to realign the lens while I had my back turned would not be high on my list of first expectations. It's not necessarily wise to suggest changing the whole tire if it only needs a little air.  |  IP: Logged Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 01-18-2004 04:54 AM                        quote: You may have a loose element inside the backing lens. When removed from the turret, give the lens a gentle shake and see if you hear a rattle. If the backing lens is suspected as the source of the problem and it's one which will unscrew from the anamorph (i.e. the two are not a sealed unit), why not just try projecting something through it on its own, and/or trying the anamorph with a different prime? That should tell you which of the two units is causing the problem.  |  IP: Logged Phil Blake Jedi Master Film Handler Posts: 558 From: esperance western australia Registered: Nov 2003 posted 01-18-2004 06:26 AM                        Thanks for the assistance. , To answer some questions , yes the focus has always been out in this cinema from new (on scope only) , we has screened a scope print in 1 and 2 , focus is fine , when screening in 3 focus is shocking. I am amazed the owners have let it go on for so long . We do have a loop of test film here. Regards Phil  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 01-18-2004 08:24 AM                     quote: This board is full of these situations, where someone asks about sticking a screwdriver into something, only to be bombarded by well-intentioned suggestions, some overly technical and probably not recommended if the problem hasn't been identified first. Eventually, someone even thinks about asking if the poster has the experience, and maybe the authorization to be taking the screwdriver out of the tool box in the first place. Seriously! "Vegas-style" wagering comes to mind sometimes. Brad's been giving Film-Tech tee shirts to "winners" again, hasn't he? Afterthought -- Curiously, the title of this thread applies to BOTH PROBLEMS being discussed!  |  IP: Logged Phil Blake Jedi Master Film Handler Posts: 558 From: esperance western australia Registered: Nov 2003 posted 01-18-2004 09:13 PM                        Manny raises some valid points here , should I be attempting to make the lens adjustments ?? , OK I have some 20 years experience and over that time i have successfully carried out all types of adjustments and repairs , however I have never needed to sort out lens issues so I will admit I lack experience with lens adjustments. If I cannot correct the intergrated anamorphic focus by simple adjustments maybe I should call the experts ?  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-18-2004 10:44 PM                     Bottom line determin what the employer expects you to do and that is it  |  IP: Logged

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