Lineup - the usual suspects

There's lots of discussion on the Cree XR-E and the differences between it and a Lux. Here is a lineup pic (Click on the image for a much larger version):

From L to R
Wahwang 3W, Cree UV, Cree XR-E, Cree 3W, LumiLED LuxIII, LumiLED K2



Paul

:kewlpics:
Would it be possible from those to estimate the difference in die height bewteen the Lux and the XR-E?

Migs, that is exactly what sparked me into taking the profile shot. I started a CAD model of the Lux and Cree. I may eventually have to destructively measure one of each to get the exact dimensions. I have lots of old Luxeons that I don't mind cutting up but not too many of the Crees!

The slug to top of die height is really a lot higher for the Lux, especially considering the Cree's die basically sits on the ceramic. Another dimension to consider is the top of ring to die height. In the very quick analysis I have done so far, the Luxeons make it much easier to design a reflector around because their die height sits higher than the top ring. The Cree is more "pre-focussed" so it needs a much deeper reflector to collimate the output.

I think I have figured out the cause of the little "horns" on the ends of the Cree's Radiation pattern. I believe it may be caused by reflection from the ring that the dome sits on.

:twothumbs

...and on the results of your modeling