How do I pick brightest 5 watt for Aleph LE?

I have one WW0T and one WX1T 5 watters that I want to use to build a (5watt?) LE for an Aleph 1 head. I will use a BB750 with a two-level switch on one RC123 or two CR123 cells. Since I will mostly use this light on low mode, I want to pick the brighter/more efficient LED out of these two.

I do have a light metter (Meterman LM631 or something like that - the one from the group buy a couple of months back), but I don't know what would be a good, reliable method of picking which one of my two LED units puts out the most light at the same drive level.

At this point I am inclined to do some setup similar to the flashlightreviews to measure total output (not trow), and if I recall it used a milk carton with aluminim paper on the inside to create refletions within the container.

I will of course clamp the star to a copper heat sink with Thermal compound and have a small 12v PC fan pointed at the "victim", but I do also have a bare emiter as well. How do I go about testing the emiter?

I would like to please get some ideas/suggestions and possible setup to test these. Maybe photos as well?

Thanks in advance,
Will

Try posting this in the McGizmo forum. The rules don't allow double-posting, so you may have to delete this post (if it's not too late) or cross-reference it.

I saw this earlier, was going to suggest changing title to something like "How to test 5W LED's brightness prior to install?"

I'm interested in that myself just for the educational aspect.

Good luck,

Mark

Will, if you use the same "optical solution" when testing all 3, the lux readings on your lightmeter should suffice. You will need to heatsink the emitter, or you will kill it almost instantly! (And the stars too- just takes a few seconds longer!) If it were me, I would Arctic Alumina Adhesive (epoxy) the emitter down to a good sink. For the stars, I would drill/tap holes in a sink to screw them down with some heat sink compound. (Tooth paste is adaquate for short term testing. /ubbthreads/images/graemlins/grin.gif )

Larry