So I upgraded my Catapult V3 from the T6 (tint?) that it came with to a U3 1C last night. I have to say the tint was very gross, even with the reflector off it was very almost green/yellow looking, so much that I reinstalled the T6 that came with the light, now it’s back to the clean white it was. It wasn’t worth the few extra lumens for the gross tint.
It was funny, I have a U3 1C in a SolarForce L2 I use for cycling (only driven at 1500mA though) and I haven’t noticed it there. Maybe it’s because the Catapult drives the LED so hard? I dono, found it funny though.
I’m driving a u3 1c up to 3.7a, I don’t see a tint shift, even after a good 10 minutes running. It’s running in an m10, which I see as a heavy duty c8 sized light, much more mass and bigger pill than a c8, plus I can stick king kongs in it for acceptable run time.
I have to say, its my current favorite light and one reason is the uniform cool white tint from hot spot to the edge of spill, I had it running for about 15 minutes outside tonight (–1 degrees c) and I was to busy admiring the usefulness of the beam, good throw with brilliant spill. I’ve also run two cells through it at work, but at much lower current levels (less than 2.6a) 3.7a is a bit ridiculous tailstanding under a van or in a white cramped refrigerated box.
Where did you get the led from? What thermal compound? I got mine from intloutdoor, I have another couple that I should be fitting and testing this week with the same driver, one in another m10, one in a ke-5. I do really like mine to be honest, so gutted yours hasn’t turned out well.
Weird, I got mine from intl-outdoor on a 20mm star, maybe there is something messed up with it. I was using Arctic Silver as a thermal compound and the Catapult should be running it around 3.5A. Even with the reflector off when I looked at it from the side the light was very yellowish compared to the T6. I was surprised to say the least. I am going to hook it up to a spare driver when I get a chance and see what it looks like then.
True, looking at CREE’s binning spec sheet, they always provide the test result @350mA. And rightfully so, testing and providing tint shift/luminosity graphs throughout current range for each individual emitter is, well, nuts. No manufacturing would undertake that, and cost would simply jump through the roof.
Driving more than CREE’s spec, you can only hope to get lucky that the tint stays close enough. Lottery it is.
My take: whenever a new higher output LED arrives [in this case a U3 ] the early arrivals are “tint orphans”. The more desirable LEDs that fall close to the dotted line in Nekdo 12s graph above are “select” and either used by Cree itself or sold to the largest vendors. The “outer limit” LEDs are binned and sold through regular channels. From what the OP described, the LED he got was close to upper 1C bin limit near the 1T or 2S bin.
