Yes, in direct drive it is easier to get maximum performance from the SST-40 than from the XM-L3, for the XM-L3 you have to take extra care to keep the resistances low in your flashlight build, even with struggle you achieve 7A max is what the numbers suggest. But then, 7A is a fine current IMO.
Thanks Steve, I guess you are right that I’m sort of retired from led testing, the procedure has become a bit boring and I’m not as curious as I was before. And there are not as many really exciting new leds as there were a few years ago it seems, progress is slowing down.
But if a really promising new led appears I will probably test it again, i.e. I’m looking forward to DIY LEP components becoming available
Thanks for the review. At last, proof that the single-die 5050 hasn’t evolved much in 6 years. I wouldn’t exactly call it an upgrade from the sst40. I think the 4040 would be of interest for innovation. Luxeon has three market cornered for that with the V, but Osram’s Boost HX is a very interesting emitter indeed.
I wonder why. The conclusions I’ve seen for 3535 footprint seem to indicate the footprint can only handle so many watts before all the emitters peak. But 5050 I’d expect to see a lot more from. Certainly the XHP50.2 3V has proven how much heat it can handle. But even the SST-40 doesn’t really do anything different than Luxeon V at 4040.
An explanation for that could be that the heat in the led itself does not spread sideways well and does not reach the edges of its thermal pad as easy as the middle. So if there is a good heatsink under the led the thermal handling is more determined by the die size than the package size.
Thanks taking the time to test these LEDs and share the results djozz. Being relatively new to the flashlight hobby just about the first thing I do when I encounter an unfamiliar LED is check your tests - they’re a fantastic resource.
But looks like the 5700K's which were in stock are out of stock now
Do you have them, or are looking to stock them at Cutter? It's an interesting LED coming from CREE, but compared to the 5000k SST-40, it's not quite there yet.
That Mouser page has part #'s down to 4000K, though not real yet.
I’m still planning to.A few months ago I have already tested a sample that Hank sent me (it tested not revolutionarily better than the 3030 version, seemed a low bin to me), and I have one that I bought from Simon that still needs testing. One of these days…