GE MQI 250w MH and UV stops...

[justme]

ace3000_1

If the warning about the halogen was directed towards me theres no need to worry.

The slide pj lamp is incandescent and since I have no idea as to what non-visable light it puts out I plan on a UV filter of some kind. Strangely enough with the huge amount of light it puts out the test slide I made by printing out a kind of test pattern on a regular piece of paper didn't seem to warm up very much at all, maybe because it's almost a foot away from the lamp.

[ace3000_1]

The slide pj lamp is incandescent and since I have no idea as to what non-visable light it puts out I plan on a UV filter of some kind. Strangely enough with the huge amount of light it puts out the test slide I made by printing out a kind of test pattern on a regular piece of paper didn't seem to warm up very much at all, maybe because it's almost a foot away from the lamp.

Ya well they dont put out much light thats why , dont forget a lcds polarisers absorb light so heat bulds up.

For that lcd an incondesent light wont be bright enough. The setup i had (when i once used a 6inch lcd) had a 150w halogen with 2 peices of uv grade plexi wedging the frensels as a uv filter, the lcd still went black. Thats why i tell people to use the proper filters because uv grade plexi wont be enough, neither will glass.

Trev

[justme]

Well I bought an old boxlight projector that uses a 250 watt MH lamp (from what I've been able to find out), maybe if I can figure out what part of the innards is the ballast I could use that, One of the lcds seems to be shot so unless I can find the same model cheap with working lcds it's just taking up room. The wiring is pretty simple since it was built around a pc case format and there seem to be only a few that carry much juice. It also seems to have lots of UV and IR protection I could use as well. This way I could at least get my $35 worth out of it.

[ELiTeHaYDeN]

Ace, did the LCD go black because of the UV output from the 150w Halogen lamp? I thought that these put out miniscule amounts of UV when compared to a Metal Halide Lamp, and if your LCD still when black then it sounds like lexan REALISTICALLY does **** all other than eat a little bit more light.

Quick off topic question :
I have ordered and have on its way a 400w HQI Light kit from Astaples, he doesnt state weither its UV blocking or not? whats the best protection for that then? will the peice of glass and UV film simply not be enough?

[ELiTeHaYDeN]

Originally posted by justme
Well I bought an old boxlight projector that uses a 250 watt MH lamp (from what I've been able to find out), maybe if I can figure out what part of the innards is the ballast I could use that, One of the lcds seems to be shot so unless I can find the same model cheap with working lcds it's just taking up room. The wiring is pretty simple since it was built around a pc case format and there seem to be only a few that carry much juice. It also seems to have lots of UV and IR protection I could use as well. This way I could at least get my $35 worth out of it.

if the lamp was relativly small form factor could you not use this? eg, attempt to use the entire light box ..

[ace3000_1]

Ace, did the LCD go black because of the UV output from the 150w Halogen lamp?

Ya nothing else would of made it black, i didnt paint it thats for sure lol. The colours changed aswell the yellow and green wer faded and the blue went darker. I didnt use the projector much, about 500hrs in total, i remeber the lamp i used gave me a good tan in 30mins.

Im not sure what that UV film is like but its a good start. Edmund optics among others sell the filters, you only need a small one.

The 400w HQI from Allan Staples is not UV blocked.

Trev

[ace3000_1]

Well I bought an old boxlight projector that uses a 250 watt MH lamp (from what I've been able to find out), maybe if I can figure out what part of the innards is the ballast I could use that,

No cos they are DC rated and they wont carry the same voltage or amperage as the AC rated lamps we use. If you did mannage to get it going it will also take the life out of your lamp as it will burn the cathade electrode out.

Trev

[justme]

I have a feeling that I wasn't very clear about what I was planning. The idea is to use the entire "light engine" from this projector including the lamp & reflector. Just mount it and all the cards in a larger case (with the cards out of the light path of course). I know from messing around with it that the lamp will function without the LCDs, TV tuner/composite input card and the VGA in/out card. Just use it as a light source. Since the fl of the condensor, fresnels and objective are longer and the LCD is larger I will need a much larger case anyway,(even using mirrors).

Here'e what I'm looking at:

[ace3000_1]

It still wont work because the light in these things are condensed and they are made to illuminate 1.8" lcd's only. They are custom made to be this way and it goes right back to the reflector.

If its got an elliptical reflector no problem, but if its a parabollic (in most cases) you wont have a chance.

Trev

[justme]

The LCDs on this thing are even smaller than that. I'll just have to pull it apart so I can get a good look at the reflector. This is just a stopgap measure since I know a replacement lamp would be expensive and hard to find.

Thanks, a appreciate all the info.