Hello, here's my first PJ

I used a 400w metal halid lamp with 36000 lumens, the lumenlab 3 lens kit, and a lcd panel from samsung 510n 15" monitor. Must say that this was a realy exciting project, and the picture quality ir awesome. I still need to build a keystoning device, and the edges are somehow darker than the rest of the image. I gues that the reason of the darker edges could be in the reflector. Could anyone help me about that?

P.S. sorry about my bad english

dark corners are probably due the focal point of the collector fresnel not PERFECTLY set on the centre of the bulb....try moving the collector fresnel back/forward ....left/right ...or up/down......most likely not the reflector.

Oh, guys, dimmer corners are basic physics, you will NEVER get perfectly uniform brightness across the whole screen. Just forget it, it is a fundamental rule, you cannot change basic laws of physics, no matter how much tweaking you apply. Screen corners are further away from the light source, thus they get less light, and it's proportional to inverse square of the distance.

Regards

While looking at your pictures, the one with green liquid and thick pipes, I was wondering what part of your projector it could be, you built some fancy liquid cooling or what. Then I realized it's a movie screen

Regards

Some more screenshots in this case the screen width is 1.80m (about 72")

Don't you think, that if I use a perfectly spherical reflector and the light soucre is perfectly in focus of the first fresnel and reflector, this would solve the dark edge problem?

No, I'm pretty sure there is nothing you can do to completely solve this problem. I don't know how much dimmer those corners are, if it's really bad, perharps something needs to be adjusted. But no matter what you do, you will always have less light in corners. Imagine light going out of the source as a bunch of identical, round, narrow beams, and what happens when these beams hit the screen. At the center such a beam forms a small circle, but in the corner it's not only a bigger circle (so less intense), but also "splashed" into kind of ellipse (even more area, so even less ligh intensity). That's it, and there is no simple cure for that. All you can do is to try set everything optimally, so the difference center-corner is not that visible. Sorry for my crappy English

Regards

just try what i said...im sure it will make it better....trust me....move the collector fresnel.....just do it! ull see

Ok, will try, thank you fo your advice

same here! LOL