On Thu, 03 Mar 2005 05:49:56 -0500, Nick Hull
wrote:

IIRC the military uses some LED flashlights with the LED mounted
'backwards' into a reflector because the beam is so much tighted so it
gets less backscatter in a dusty environment.

That might be the Pelican Recoil.
http://www.pelicanaustralia.com/ledlites.htm

Similar idea, but this requires a fairly large reflector so the 3/8"
dia body of the LED and its support structure don't present
significant obscuration.

I believe Ian Stirling is/was contemplating this configuration using a
sapphire lens as both support and heatsink.