A guy has a neat looking light engine here:

http://www.lumenlab.com/forums/index.php?showtopic=8052


Cool looking but how exactly does that work? (how does it effect the light) and what kind of improvement does it make?

Its a condensor, it takes the light that might be spread over a 60º Arc and concentrates it to a 45º arc ( actual numbers depend on the lens). So if the bulb is at 220 mm from the lens normally you would get only the 45º worth of light but with this lens you compress 60º worth of light into the 45º angle that hits the fresnel/LCD. Guy Grotke over at diyAudio has had a discussion of this he thinks its of limited use at 15" little use at 17"+ and mostly useful for smaller pannels as the larger panels are already getting a pretty big angle and there is some light loss passing through the lens so you might get 10% gain with 10% loss. The angles with a 7/8" panel are small enough that the extra light could be significantly more than the 10% loss in the lens

Nothing comes for free. When dealing with pre-condensers you have to take into consideration the magnification it has on the arc. Although you might be able to collect more light it may not fit through the triplet.
I agree with what guy grotke at diyaudio says but I believe that adding a pre-condenser to a 17” LCD may more evenly distribute the light, less dim corners, I still need to test this though.

DJ

For a 15" or 17" panel, I think that this would be the only real justification for such a lens. Direct more light at the outer area than you do to the center in order to compensate for the square law losses, as well as a "fudge factor" for additional losses due to scattering. An aspherical lens would be required to pull this off.

With the smaller panels, not only are you magnifying the arc, but you are also introducing square law losses, similar to that of the larger panels. when it all boils down, this is a function of the angle size of the light cone that you capture.