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Author Topic: Best way to focus strong Super Highlight Michael Voiland Expert Film Handler Posts: 219 From: Naperville, IL US Registered: Aug 2009 posted 08-29-2009 10:58 PM                     I recently saw this issue with one of our strong super highlights. It seemed dim when our intro short was playing. The whites appeared gray and not that crisp clean white that you expect to see on white text. After the film got out of the projector we went about and tried to focus it, but I couldn't get a good sphere of white light to bring out. When I did get a bright light as in the center of the screen as I tried to even out the screen the sphere skewed and wouldn't spread evenly. This projector has a 2k bulb. The head is a Pro 35 with a turret. This projector had a projector bulb explode in it a few months ago so I am looking at this as being a cause but it seems to be really apparent now because it looked fine for district 9. I am new to projection but I have always been technical and I have done a good amount of reading. I have been working with film since early July.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 08-30-2009 02:51 AM                     Did they replace the reflector after the bulb exploded?  |  IP: Logged James Westbrook Phenomenal Film Handler Posts: 1133 From: Lubbock, Texas, Usa Registered: Mar 2006 posted 08-30-2009 03:13 AM                     Welcome to Film-Tech, Michael. I am guessing the bulb had it's "catastrophic failure" (exploded) before you were promoted to projection...do you know off-hand if the mirrors and reflectors were left "as is" after the explosion or were they replaced? Was the cause of the explosion determined? (poor or no ventilation or cooling for bulb, excess hours on bulb, higher than rated voltage). Did a technician make any repairs to the lamphouse after the explosion? There are so many reasons for the less-than-white light you are describing, that I am sure we will need more data before the probable cause is known. We could be looking at misaligned optics in the lamphouse (mirrors and reflectors), projector lenses that may need replacing, an undersized lamp for the size of the screen or throw to the screen, the lamp not getting enough current...I am sure the more seasoned techs will chime in with probable reasons as well. The following should help us determine the likely cause: Exact model of that Strong Super Highlight (there should be a plate somewhere on the outside of the lamphouse, or console, whichever it is), the brand of xenon bulb that is being used (we know it's a 2K, or 2000 watts, but different manufacturers produce different quality bulbs). Are you able to determine using the amp/volts meter what amperage and voltage the bulb is running on? That would help, too. You are probably aware that flat-ratio movies like District 9 will look dimmer, comparatively, than Inglourious Basterds, which is scope ratio because of the aperture plates of the scope movies allowing more light onto the screen than the flat aperture plates. Once we get the requested data, we can get to troubleshooting.  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 08-30-2009 03:15 AM                     quote: Jeremy Weigel Did they replace the reflector after the bulb exploded? LOL Imagine if they didn't! Well the best way to focus a lamp or a reflector is without a lens present. You need to adjust the lamp verticaly and horizontaly until you see the black bullseye spot exactly in the middle. Then you back out or forward the lamp until it gets brighter and brighter. Then you insert a flat lens and back out or forward the lamp in the reflector. You should see all 4 corners of the screen dim equaly if you made it all correct. Also check whether your bulb has blackened or the reflector has damage on it (considering that it should be new). Demetris  |  IP: Logged Michael Voiland Expert Film Handler Posts: 219 From: Naperville, IL US Registered: Aug 2009 posted 08-30-2009 11:27 AM                     Well I was in training the bulb failed. It was a superior 2k bulb, The failure was caused by a failed fan in the super highlight. They did not replace the reflector and I have not taken a close look at the reflector yet. I will take a look at it soon. The company I work for will be opening a new theater next week and I will be transferred there so I wont be working on these projectors much longer but I was just very dim when I looked at it.  |  IP: Logged James Westbrook Phenomenal Film Handler Posts: 1133 From: Lubbock, Texas, Usa Registered: Mar 2006 posted 08-30-2009 01:43 PM                     Is the theatre you are currently at about to close? If so, that is possibly why the reflector didn't get replaced.  |  IP: Logged Michael Voiland Expert Film Handler Posts: 219 From: Naperville, IL US Registered: Aug 2009 posted 08-31-2009 11:36 AM                     No we are opening a new location thats all. I took a look yesterday the reflector is scratched pretty bad but it also looks like it wasnt cleaned. It needs to be replaced but the bulb failed in the middle of a show so I think it wasnt cleaned. I need to track down a bulb box and then I am going to take the bulb out and clean because there is still glass in the lamp house.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 08-31-2009 12:16 PM                     Focus needs to happen with the SCOPE lens, not the flat (or not exclusively the flat). Scope uses more image area than flat does (55% more), so your corners can be bright in flat and dim in scope if you don't check it. --jhawk  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 09-02-2009 10:52 AM                     Try checking the light pattern with no lens. You should have a dark spot with bright concentric rings, more or less. You will see the shacdow of the anode cable, don't worry about that. If the rings of light are way distorted - they should be circular - then your mirror is distorted and will never give flat light. A bulb explosion can distort the mirror as well as scratch it if a largish piece of the lamp hits it. Move the rear adjuster around to get the light circle pattern concentric around the dark spot. If the rear adjuster is way to one side or up/down, move the front lamp support the same direction as the rear adjuster is off centre. This improves the light a bit by reducing the anode shadow size but also makes adjustment a bit easier. Once you have centred rings around a spot pattern, put the scope lens back in and have a look. If the hot spot is not roughly centred now, the lamp tray is not aligned properly with the projector. Note that with top only masking you shift the lens up and down to align the scope and flat images, so one or both will have the hotspot high or low. Aligning the lamp tray is not easy, attempt it at your own risk. The console came with a string alignment kit that will show if the mirroor is pointed exactly at the lens centre insert tool, but there are other issues. If you have top only masking, one or both lenses will not be on centre. The lamp table can be high, low, or off to one side and still be pointing the mirror at the centre of the lens insert. You have to get the lamp table adjusted so the string goes through the centre of an aperture plate to the centre of a lens tube either on centre or between the shifted scope and flat positions. Once you have that and the string is in its shadow viewed from top and side you have the best position the string method will give. Naturally you must have the mirror at the correct working distance, measured from the rear hole edge to the film plane. Thos measurement is in the console manual. If the mirror is badly scarred or distorted, replace it. There's no way to polish or reshape them that would be cheaper than a new one. There are two mirror sizes used, with a 2K you probably have the smaller one if the console is reasonably new.  |  IP: Logged Michael Voiland Expert Film Handler Posts: 219 From: Naperville, IL US Registered: Aug 2009 posted 09-03-2009 03:06 AM                     That is a picture of the lamp house. I believe the year is 81 or 91. The projector is a pro 35 with a turret and the flat and scope lenses in it.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 09-03-2009 05:09 PM                     I have six of these consoles (installed in 1988) with 2 that have been decommissioned due to digital installs. Bulb adjustment on these is a pain in the ass mainly due to the design of the focus control. It tends to raise the front of the bulb when adjusting the the bulb back into the reflector and vise-versa. This causes the vertical alignment to get thrown off. The other problem with the focus control is that the cable attaches to one side of the skid and the other side has a guide pin and the skid tends to "bind" due to the torque on the skid, so as you're making adjustments to the focus the tension on the skid will release and "pop" your adjustment out of whack. Another thing to be aware of is to make sure that the threads on the adjustment rods are not seized up before you start trying to turn the cable or you could snap the cable.  |  IP: Logged

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