This is topic Orcon Lamphouse Mirror Replacement in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by John Cruz (Member # 6531) on 10-25-2011, 01:58 PM:
 
Hi,

On several occasions when accessing the "lamp chamber" in our Orcon CV 2000 lamphouses, I noticed the 45 degree mirrors were oddly discolored. One of our lamphouses has greenish streaks (they look more like scratches or very thin, long cracks) on the mirror where the vertical xenon bulb light is reflected off of. Another one has a purple discoloration in the same area. Both of the mirrors I recently saw are also slightly translucent, at least on the edges of the mirror where I noticed this. I can't recall how the other mirrors look right now, but my guess is that they are similar in appearance.

My question is, when should the mirrors be replaced? I found two brand new replacement mirrors burried in our booth. As far as I know, the current mirrors haven't been replaced (or cleaned) for 5 years at the very least.

I was searching for threads that would answer my question but came up empty handed. I did read that the lamphouses should be cleaned, and the blower should be dust free. Our lamphouses have a very thick layer of cotton-like dust all over the place, including in the blower, wiring, etc... (I am assuming cleaning that should be on my priority list now that I know ) The door to the "xenon bulb chamber" has instructions on how to clean the mirror. I will give it my best shot (unless that is not a good idea for some reason), but was also wondering whether both sides of the mirror should be cleaned. The side reflecting into the projector is a bit dirty, but not nearly as bad as the flip side, which has noticeable dust accumulation on the surface.
 

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Posted by Louis Bornwasser (Member # 3063) on 10-25-2011, 02:15 PM:
 
You can also "reverse" the oblique reflector. Swap the 2 parts so that the unused (good) reflector is at the center and the bad parts are away from where the light is. Louis
 

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Posted by John Cruz (Member # 6531) on 10-25-2011, 02:54 PM:
 
Louis, great advice.

I noticed the "mirror" / reflector is composed of two separate smaller mirrors. Are you saying I should swap those (put the one that is on the "bottom", currently not reflecting light, on "top") or should I just flip over the individual mirror that is starting to "fade"?

As a side note, does the picture quality suffer if the mirror is left unchanged for a (very) long time? We had a distributor come in with a tech last week to tech a film they were opening and the tech said we were within the SMPTE standards, almost dead on 16 footlamberts (through the portglass in the booth) on the screen with the green "scratched" mirror.
 

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Posted by Sean McKinnon (Member # 612) on 10-29-2011, 01:55 AM:
 

quote: John Cruz

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through the portglass in the booth

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Ugh!
 

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