I'm using a standard OHP (like what school uses for those transparency papers) for my PJ right now. In it, it has a 600W Filament bulb. It gets VERY hot, and doesnt produce very good color nor light (blacked out room only to watch). I'm currently upgrading to a 400W Metal Halide bulb, which I know will give me much better color rendering. However, how much brighter shall I expect? Does one think, viewing in a slightly lighted room is going to be possible? I also have new everything on the way, so the old PJ is going to be trashed, and a new one with all Pro parts will be made. I know there is ALOT of room to make the PJ better, but I just want to know how much better can I expect?

that's kind of hard to answer since none of us know exactly what kind of results this 600w bulb is giving you.

I was able to watch my projector in a partially lit room if i made sure that it was not exposed to any direct light. (no light sources could 'see' the screen) but it always looks better when its darker.

I found this 600w filament (halogen) bulb which gives 17,000 lumens and is probably crazy crazy hot.

http://www.topbulb.com/find/Product_Descri...oductID_E_43769

the 400w MH bulb is going to give you around 32,000-40,000+ lumens so much brighter, much cooler, and much better color temp. The only downside is it takes a little longer to get to full brightness.

Seriously if you're wanting to make a movie room you're going to want it to be as dark as possible...even a little light and you start losing contrast..this is true of any projector.