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Author Topic: Proper Lamp Alignment Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-23-2007 09:55 PM                     This is something I have been trying to figure out for some time and hopefully some you can help me correct this. Below are some pics of while I was thrying to align a lamp today. Image 1: Bulb focused almost completely to the back of the reflector so as to position bulb image in the center of the reflector rear opening (not centered at the time of the pic). Problem is that the image of the reflector's rear opening appears distorted not spherical. Image 2: Focus adjusted so that I get a somewhat crisp bulb image, but I can't get the "4 even dark corners". Hopefully you see that the left corners are brighter than the right corners. Image 3: Focus brought forward to see if the concentric rings colapse as evenly as possible. They don't. As you can see the left side completely colapses well before the right. This is a Strong SuperHighlight(1988). I have performed a string alignment test and the string image on the reflector checks out. The optical bench itself is stationary, so I can't adjust it like you can the SuperHighlight 2's. Any suggestions?  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-24-2007 01:07 AM                     Is the back end of the mirror on the outside showing any results of excessive heat - like where the outside surface is showing a bluish color from the opening to about 4 to 6 inches towards the front? Bet the back end of the mirror's is warped. Take it out, lay it on a flat surface, place a straight edge across the back of the mirror to see if any high spots are noticable on the back end where the cathode end of the bulb comes out of.. If so, time for a replacement mirror.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-24-2007 02:31 AM                     I'll certainly check on that in the morning. It is quite possible since we didn't have dedicated HVAC in the booth up until 10 years ago when Regal added 2 screens and found out there was no HVAC. Man, summers were brutal up there. Sometimes it would get so hot that the old Strong high reactance rectifiers (have since all been replaced with switchers) would shut down in the middle of a show. I don't know why the Litchfield company who originally built this place didn't spec in HVAC for the booth. We probably lost more money in refunds during the summers between '89-'94 that could have been prevented with spending some extra $$ up front. Ah well, at least I got to come to work in shorts and short-sleeve shirts while everyone else was stuck in a long-sleeve shirt, dress pants, a tie, and the dreaded vest with fake pockets.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 04-24-2007 03:25 AM                     (Actually, the HVAC history in that booth wouldn't have any affect on the mirror condition - being that is two completely different ventilation areas). Main thing that cooks up mirrors is when the bulb is focus too close towards the back of the reflector-which is producing an extremely bright, almost too bright of a picture, plus not enough exhaust up the stack to pull out all of that heat, esp if you have a large bulb in that Highlite Console. What size of bulb are you using? Trick on bulb focus, is .. true you did the coarse adjustments in getting the 'looney tunes' on the screen and centering the rear end of the bulb to the front so there will not be any 'blisters' arising around the shadow of the anode that shows up on the screen. But, the fine focus is when you throw the light on the screen through the scope lens and adjust for the even field of light. (And, if you have a large bulb, open and close the hand dowser every other minute so the scope lens doesn't get too hot since there is no film passing through the running machine to absorb some of that heat..) You adjust for lateral/vertical for field and focus for elimination of the dreaded 'hot spot' - the bright glare in the middle of the screen.. You move the bulb until the corners start to darken, then move the bulb the opposite direction to get the corners to be even with light, then, keep on moving the bulb until the light just begins to dim..this is where you want the fine focus to be at. Why the dim is so you don't get excessive flutter on the screen from the light being focued on the shutter instead of the aperture opening. good luck - Monte  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-24-2007 03:46 AM                     But doesn't the cooling system also rely on drawing in cooler air outside the lamphouse? Anyway, I'll certainly give that and a couple of the other reflectors that have the same problem a good once over. As for lamp size, all 8 screens run on 2k's. I have our HVAC techs out to do our annual AC check up and I am also having them to check our CFM on the stacks while they're out. I was always told to bring the focus in until I start to get shadowed corners then back out just until the corners were evenly lit with a uniform light field across the screen. Haven't ever had any problems with flickering images on on bright scenes stopping focus at this point. BTW, does anyone rent out the PSA-200?  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-24-2007 11:41 AM                     Well... pulled the reflector didn't see signs of any excessive heat. The black coating on the back is in good shape. However, it looks like the bottom end has been flattened out a little and orange/red silicone around the reflector and its frame is of course dried out and cracking. I measured the diameter across from top to bottom and came up with 15 1/4" and a measurement across side to side of 15 3/8" so it is about an 1/8" out of round.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 04-24-2007 02:29 PM                     my suspicion is possibly that you need different bulb adapters and that the reflector is not at 90 degrees to the lamp axis  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-24-2007 02:33 PM                     I agree with Gord on this. Reflector to projector(optical) alignment is quite critical. I reccomend the Kinoton alignment tool... expensive but runs rings around the rest of whats available out there. Also... looks like you've got an older Strong reflector there. Note that the RTV that bonds the ring to the feflector is beginning to deterioate. Sometimes the reflector slips out of alignment in the ring when this occurs. Eventually the entire ring will seperate from the reflector. Strong has changed this design(like everthing else they make) so there is no bonded ring to seperate any longer. If you replace it be sure to get the needed parts to be able to mount the new reflector in place of the old one. Mark  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-24-2007 04:51 PM                     Went ahead and ordered a new reflector. Its listed as a X-60 reflector. Do you guys think it is worth having the old one reworked by someone like UltraFlat since Strong doesn't do a repair/exchange on reflectors. Also checked to make sure that I had the correct bulb adapters and they are the correct ones. Should have the reflector by Thursday.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-24-2007 05:44 PM                     Hopefully you ordered the mounting adaptor as well. Or you won't be able to mount it in place. I would say to pass on re-working the mirror... two reasons... 1. Ultraflat does not do Dichroic coatings which you will definately need. Adding a schnood type heat filter is not always adaquate dependng on your lamp size. The mirror restoration and heat filter will end up costing you way more than the new dicro mirror from Strong. 2. The price of an ultraflat restoration is generally within 15% to 20% of a brand new mirror... +/-... depending on the pricing your dealer gives you. Hopefully cost plus.... And you still won't have the dirco coating you need. All in all Ultraflat does top notch work but there has never been any real savings available that I've seen. I've only used them in situations where there is no NEW mirror available. Mark  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-24-2007 05:58 PM                     Mark, How long have they been using a mounting adapter? I had to replace a reflector back in Sept. '05 when I had my first and so far only bulb explode. The replacement was a simple swap-out. I simply used the same part# off that invoice to order this one.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-24-2007 06:58 PM                     I know the Super Lum-Ex requires an adaptor since they eliminated that bonded ring and the flange is now at the front edge of the reflector. I thought they also did that to the Highlite-2 but I may be thinking of the original Highlite. Looked aat your pics again and it does appear that the ring is at the front edge. Mark  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 04-24-2007 07:03 PM                     Just realized that I still had an email address for Troy James at Strong so I shot off an email to him just to double-check.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 04-25-2007 12:52 AM                     The newer mount requires more critical alignment since the reflector can be adjusted in the mount  |  IP: Logged Michael Schaffer "Where is the Boardwalk Hotel?" Posts: 4143 From: Boston, MA Registered: Apr 2002 posted 04-25-2007 07:24 AM                        quote: Jeremy Weigel Do you guys think it is worth having the old one reworked by someone like UltraFlat since Strong doesn't do a repair/exchange on reflectors. You can also wear it as a helmet. The holes on the side are practical for chin straps. The hole in the middle can be covered with some kind of feather arrangement or similar, depending on your status in the tribe. I wouldn't have tossed it out as quickly though. Like the gentlemen above said, it is very obvious from the images that the reflector is not at 90 degrees (damn, where is that small degree symbol on American keyboards?) to the optical axis. The string thing is OK, but adjusting that according to what you see on screen is a much better refinement. Like Mark said, the Kinoton alignment beamer is a great tool for reflector alignment. It goes into the lens collar instead of the lens and it projects a green halogen light into the reflector. The end facing the reflector is flat, and you can see the light coming back from the reflector as a circle (hopefully) around the light opening. It is extremely helpful to make sure reflector and alens are in good alignment, but a little problem remains with projectors where you can open the lens turret (Kinoton's don't, so you can *basically* rely on the lenses to be always more or less at 90 degrees to the optical axis). Because if it can be opened, you don't quite know in what position the turret is. I find that the most problematic aspect of projectors with opening turret, and apart from the extremely expensive alignment gauge the people at Strong have, I don't know what the best way is to make sure the turret and lens collars are at exactly 90 degress to the optical axis. Seeing how even the focus is on screen with test film helps a little, but that includes other factors again (lens evenness). I usually focus on the sides of the aperture plate. If those aren't evenly in focus, it is typically an indication that the lens turret is not correctly aligned to the aperture. It is typically best to center the bulb focus and work with the front support, only use the focus to finetune, if at all, and later, to adjust to individual lamps. In your example, if the lamp focus was centered, the front support would have to go up maybe just a little (remember the reflector reverses the image, so on the screen, it will go down), hard to tell because of the unevenness of the reflector hole. But, of course, many lamphouse types, like the original highlights, don't allow you that, so you have to work with a number of techniques, depending on what you can do with the lamphouse. Also remember that when the lamp focuse is in an extreme up/down or left/right position, when you pull the lamp back, it will not travel along the ideal optical axis, but along that axis. That is why even with a good preliminary picture of reflector and bulb on screen, you can still have a hard time finding good even focus with even corners. Also, don't forget to check that the arc is really centered between the electrodes (magnet), because if not, it can really mess up your alignment.  |  IP: Logged

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