What do you need to get MHB to work?

[Teapot]

I recently bought a 3M 2100 OHP off Ebay which was listed in the sale at 4000 lumens. Well, I found out through reading the documentation that it was only about 2000 lumens! I don't want to go through the hassle of returning the projector and it appears that the lenses are intact, so I was wondering if I could replace the bulb in it with a metal halide bulb to boost the light output. I've done some searching through the threads and found references to ballasts and the like, but nothing that covered this particular question.

Any suggestions?

 

[sadd3j]

Hey Teapot,

What you're talking about is retrofitting your OHP. A lot of us are going this route.. here is one of the originals that most of us approximately base our design off of:

http://members.cox.net/rolm/update/

The main issue is to what kind of stuff you want to retrofit it with. You can only change the bulb, but there's no guarantee that it'll work well (depends on stuff like the bulb) or it'll work as well as you want.

You can also do other stuff like add a reflector (for a bulb which doesnt come with its own reflector, two ended HQI), a condenser lens, split fresnels etc.

I'm also in the same position as you.. I'm replacing the bulb in my OHP with a new one. Of course my OHP has 0 lumens (it's broken) soo... yeah.

Anyway, do a search for "retrofit" or posts by ywh, cruser, proto5, gui999 (there are lots more people, those are a few I remember seeing some good threads on what they've done). You'll find a TON of information about retrofitting etc.

Good luck!
-rep

 

[Teapot]

Ok, i've gotten the projector all set up and working with a retrofit of a MHB. However, even with the new, ultra-bright bulb, the image is far too dark, even in complete darkness. I've got a 250W MHB with a reflector in back and a semispherical glass lens right in front of it. The mirror is a bit dusty, as is the fresnel, but I assumed that wouldn't reduce the light by THAT much (I'd estimate that the brightness of the image is about half of what I'd like it to be).

Any suggestions for increasing the light output, other than upgrading to a 400W bulb and throwing away my 250W system?

Thanks,
Bryan