This is topic Xenex L-1000 Focus Problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Aaron Mehocic (Member # 15) on 04-11-2000, 11:48 AM:
I'm having trouble focusing bulbs inside a Kni-Tron L-1000 lamphouse. Anyone else have this problem? I put in brand new ORC XM2000 bulbs, but can't get them to burn very bright. The amps gauge reads 80, so I know this is not the problem. I correct the verticle and horizontal positioning, as well as adjust the knob located at the front of the lamphouse itself, but nothing seems to work. The reflector is NOT pitted, NOR is it dirty. The anode end of the bulb is barely inside it's support bracket since I have to slide the bulb back so close to the reflector just to get light on the screen. No foreign objects are blocking the light path either. It drives me crazy! Any help would be appreciated. I've installed many bulbs during my years in the booth, but this is a situation I never have encountered.
Posted by Michael Barry (Member # 237) on 04-11-2000, 12:10 PM:
Perhaps the reflector/mirror needs to come forward? That might explain why the anode end of the bulb is barely supported by the bracket just to get something on the screen, as you say...A shot in the dark...
Posted by Richard Hamilton (Member # 321) on 04-11-2000, 08:36 PM:
Just a thought here...It sounds like the model L-1000 is a 1k lamphouse and you said that you are putting in 2k bulbs? Maybe you don't have the right bulb adaptors?
Posted by Aaron Mehocic (Member # 15) on 04-11-2000, 09:58 PM:
I questioned this myself when the lamphouse was installed, but the tech told me a 2k bulb will work.
Posted by Richard Hamilton (Member # 321) on 04-11-2000, 10:35 PM:
I would still check and make sure that you had the right bulb adaptors for a 2k bulb. Rick
Posted by Alan Brandt (Member # 426) on 04-12-2000, 01:33 AM:
My advice on this particular subject is that you'll eventually wear out what is called the mirror. In many cases, this object will flake, causing particles of glass to "cloud" the bulb during focusing. Try gently stripping the gears of the horizontal wind. That way, when you focus, it will be easier to position the bulb, without having gears to contend with.
Posted by Richard Hamilton (Member # 321) on 04-12-2000, 09:14 PM:
You said that you questioned the tech when they were installed, which I take it they were installed recently? Did you ever have good light when they were initially installed? Could it be bad alignment?
Posted by Aaron Mehocic (Member # 15) on 04-12-2000, 09:27 PM:
Yes, originally the light output was sufficient. However, The last two bulbs darkened quickly (within 800 hours), and the present bulb was installed dark. I'm going in tomorrow morning to move the reflector and bulb around some more. Hopefully this will help some. I hate bulb changes in this lamphouse. It is very touchy and hard to get optimum output. Thank you for your help so far.
Posted by Gordon McLeod (Member # 33) on 04-15-2000, 12:23 PM:
Is this the same make of lamp that was originally installed?
Some bulbs have different lengths for the same code
The L1000 is a Xenex 1 lamphouse and is usuable up to 4Kw with the extra cooling
If lamps are going black it sounds like that the lamp is getting too hot check the exhaust
Don't move the mirror. It's distance to the apperture is 28" and if you change that then you will have terrible light distribution and possibly scorched film
Move the lamp not the mirror if the working distance is correct.
Posted by John Wilson (Member # 269) on 04-16-2000, 01:28 AM:
quote:
Originally posted by Alan Brandt:
My advice on this particular subject is that you'll eventually wear out what is called the mirror. In many cases, this object will flake, causing particles of glass to "cloud" the bulb during focusing. Try gently stripping the gears of the horizontal wind. That way, when you focus, it will be easier to position the bulb, without having gears to contend with.
Was this one supposed to have a smiley face after it too, or should we be afraid...?
------------------
"It's not the years honey, it's the mileage".
Indiana Jones.
Posted by Pat Moore (Member # 380) on 04-16-2000, 10:40 AM:
"Stripping gears" worries me...
If the bulb is the same type as what was originally installed in the system, something else is wrong. I agree that there may be some mixup in adapters and that the bulb isn't quite in the right place. I never thought these lamps were too bright in the first place. Is this a glass reflector? Is the coating peeling off?
Posted by Gordon McLeod (Member # 33) on 04-16-2000, 11:08 AM:
I always got a good light out of a L1000 but alignment is the key
I wonder what gear is stripped as the focus has no gear asa rule in the xenex 1
All there is is a threaded rod coming inside from the front with a nut on the positve carrage that draws the lamp forward and back
Also check if the bushing in the mirror is the right one for the lamp. It maybe too tight or the nuts on the carrage are jammed
Posted by Aaron Mehocic (Member # 15) on 04-16-2000, 08:21 PM:
Gordon:The original bulb was a Christie CXL-20r. We got almost two years of service from this particular bulb before removal. The company than switched to ORC and the light has been shit since. The carrage moves perfectly and the bushings are all correct. 28" sound like a possible key to the solution. I'm almost certain the mirror is closer to the aperture than that.
Pat:
The reflector is glass, coating is good.
Posted by Mark Gulbrandsen (Member # 72) on 04-16-2000, 10:47 PM:
Aaron,
Get them to go back to Ushio/Christie bulbs. They are the best bulbs made! Everyone I know has had troubles with ORC lately. Its actually amazing they are still around...having been bought and sold several times since Strong bought the projector end of things. Your company may be saving a few bucks right now, but in the long haul its a big mistake and it will end up costing them money to go with ORC. Also be darn sure the exhaust system is functioning properly here. The mirror is glass and has a dichroic coating and any peeling would be noticable by shining a light through the back of the mirror. The 28" focal length is also very important to check. I've always gotten really good light out of the Xenex-1. Better than some new xenon lamphouses that are on the market. Alot of people hate glass reflectors, but the best lamphouses you can buy(Kinoton) all have glass mirrors. The Xenex-1's are a bit flimsy in places, but care in proper setup here will pay off.
Mark
Posted by Aaron Mehocic (Member # 15) on 04-17-2000, 03:21 PM:
Mark,Yes, Christie was a better bulb by far! I've argued going to Ozram since the changeover, and I have even told the owners that they would save money in the long run with another company, but they don't want to hear it. Everything for the short-term nothing for the long I guess. I hate the way an ORC flickers at startup after about 500 hours. I didn't have that on a Christie until way, way, later and NEVER had it on an Ozram! Thanks for your input.
Aaron