It was a long time since I have logged in here… My interest in flashlight modding and building faded, and because this new forum software gives me a headache I didn’t feel it was worth hanging around here. Don’t worry though, I probably won’t be back for long.
Anyhow, what got be logged in here is to ask if anyone has tried out any of the LEDs mentioned in the topic in a flashlight? The Cree XM-MR seems very new, so maybe no one has actually got their hands on any? And I have read about the SFT-42R and seen a video or two, but the one mainly used (as from what I can tell) is the 6500K one.
There doesn’t seem to be any LED tests for the SFT-42R? I would have thought that someone here would have tested it by now. Or have I just failed miserably in finding it?
SFT-42R can handle a little bit more power, 10A seems to be safe if heat managed properly. You can buy flashlights with it at Simon’s shop already.
In my opinion it performs similar to SFT-40, but gives better defined Hotspot
Thanks. It does seem to be an interesting LED. It seems to be one of the more suitable round LEDs for a 1S buck driver, the forward voltage seems to be low enough. I’ll be putting it in a zoomie (Brinyte B158) with a buck driver and run at at maybe 6 amps max.
It is possible that the emitter is driven well under 20A, due to Vf rise of the LED and voltage sag of the battery under load. 20A driver means that it can output up to 20A under ideal conditions, not in every instance.
Yeah, I don’t disagree. I only bring it up because every time I post these numbers, I get replies that seems like people are borderline offend that I’m intentionally over-driving it. In reality I thought Convoy 20A driver (similar to the 6V8A) doesn’t actually supply 20A.
Welcome back! I remember you from my first visits here in 2019.
The sft42R is pretty new and hasn’t been formally tested, but it’s performance is simailar to the sft40w. The advantage ia that the 42r is better for primary optics or aspheric lenses. It can also get brighter on paper, but you can drive the sft40w harder so that one is a bit more resistsnt to direct drive. The XM-MR isn’t one that ive seen before. Could be a remake of the sft42R and Cree data shows it has a drive ceiling of 14 amps and a somewhat low vF. Thermal resistance is .6 C/W. The fact it’s available in 5000k is nice too.
Yeah, I read somewhere here that it was suggested that Cree might have rebranded some Luminus LEDs. If that turns out to be correct, then I guess this is just a natural step.
There are still some interesting differences between the SFT42R and XM-MR:
Size of LES: 2.26mm diameter for XM-MR (4.01mm^2) versus 2.32mm diameter for SFT42R (4.23mm^2). Unclear whether this indicates they use different dies, or just slightly different amounts of phosphor coverage.
Phosphor mix. The Luminus cool white, low CRI phosphor is uniform in color (likely a single-component, broad-spectrum yellow phosphor), while Cree’s cool white, low CRI phosphor has visible multi-color patches, indicating a multi-component phosphor. Thus, a slightly higher CRI should be expected of Cree emitters.
Yes, if the emitter Vf is lower than the battery voltage sag and other resisyance voltage sag. Someone measured 14A with a FET driver, so the 20A buck schould be similar in practice.
Mouser is getting them too. It appears they will be available with the exact same color temperatures as the Luminus SFT-42R. At least according to Google there is a 5000K variant of the SFT-42R but I can’t seem to find any seller that has them. Are they not available yet? I find it odd that the SFT-42R isn’t listed on the Luminus website.
I do prefer to get my LEDs already on MCPCBs so for now I’ll settle with an order at Kaidomain for the 5700K variant.
