Don Foreman wrote:
On 03 Mar 2005 23:37:13 GMT, Ian Stirling
wrote:

Don Foreman wrote:
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.

I am, I'm wondering at the moment if extracted dies from luxeon stars
is indeed the best way.

Keep us posted, Ian! I use emitters rather than Stars, but
extracting the die would be well beyond my ability. I figure the
die is about 1 mm square while the emitter body is about 8 mm dia,
so you'd gain a little if you could do that. How much you'd gain
would depend on the reflector diameter.

I'd like the total diameter of the light to be about 17mm or so, with a 14mm
or so clear apature.
8mm is really annoying in this case.
However, getting it to 5 is pretty easy.
I'm also investigating other ways.