FiddleCaver wrote:the Q5 is just a different bin cree. Honesly, I would put the rebels in the Mo Betta category simply because they don't have either the brightness or efficiency of the SSC or the XRE. Brightness wise, you won't get any better than the SSC P4 (240 lumens), but they tint everything blue. For efficiency, the Cree XRE (228 Lumens) are the best and are just under the brightness of the SSC. The deal with the rebels is they are REALLY small and so you can put a bunch of them in a small space, but it seems to me that heat would be more of a commanding issue with a less massive product. Right now the best available rebels are at about the same efficiency and lumen output as the old P4 bin Cree (140 lumens) which was about 5 bin advancements ago.
Erm...I've been hanging out on candlepowerforums for about a year, have done LED upgrades on about two dozen flashlights and headlamps, and consider myself relatively knowledgeable about LEDs, and I have issues with some of the statements made above.
1. "Honesly, I would put the rebels in the Mo Betta category simply because they don't have either the brightness or efficiency of the SSC or the XRE."
The Luxeon Rebels are on par with the SSC P4 and the Cree XR-E.
For proof, see the third chart (efficiency) in this thread:
http://www.candlepowerforums.com/vb/sho ... p?t=171365
2. "SSC P4 (240 lumens) but they tint everything blue"
I'm not sure why you say this. The SSC P4 has different color bins just like the Luxeon 1, III, etc. To see the color bin definitions for different LEDs, see this thread:
http://www.candlepowerforums.com/vb/sho ... p?t=156772
If you're talking about overdriving a SSC P4, yes, it will shift the tint to a bluer color, but this is true for all white LEDs, because they are a blue LED coated with phosphor which absorbs the blue light and re-emits it as white, and if you dump more blue light into the phosphor, it can't absorb it all so the overall light output is shifted towards blue. If you start with a warmer tint (reddish-yellow white) LED and overdrive it, then you can have a less blueish overdriven light.
3. "For efficiency, the Cree XRE (228 Lumens) are the best and are just under the brightness of the SSC"
Well, the SSC P4 uses the same raw die as the Cree XR-E. Seoul Semiconductor buys them from Cree. so it's the exactly the same. There's differences in the viewing angle because the packaging is different, and very slight differences in efficiency because SSC seems to use a different phosphor coating than Cree, but the die is the same.
It's not really meaningful to compare the efficiency of the Cree XR-E vs Seoul for this reason. You could compare the efficiency of various bins which would make a little more sense.
4. "Right now the best available rebels are at about the same efficiency and lumen output as the old P4 bin Cree (140 lumens) which was about 5 bin advancements ago."
If you look at the third chart in:
http://www.candlepowerforums.com/vb/sho ... p?t=171365
You'll see that the Luxeon Rebel they tested (NVND bin) has better efficiency than both the Cree XR-E P4 bin and the SSC P4 they tested (probably a U-bin).
Toshi