I'm sure there is more info about it if you searched the forums.
My theory is, if you are in a situation where you need a 36v lamp in a handheld light..... then you should also be concerned about what size bullets to use.
cheers for that. all part of the research. iv just modified my lightforce blitz with a 36v 400w projection bulb, unknown make and 2 panasonic 18v 3.5 ah batterys and interested to know whats out there to produce the tightest beam.
The Philips 23177 (36V, 400W nominal) is prettybright.
You could try a reamed out aluminum Mag reflector, or possibly something from Edmund Scientifics. On the above linked build, I'm using an ellipsoidal reflector, although I'll probably break down and get a parabolic eventually.