who is buying me a XP-E2 Torch led? Update: DBCstm did, test is in post#81

Flashlight Modding and DIY Parts
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…and Hello guys BTW :slight_smile: :slight_smile:

I can test an E2 Torch de-dome vs a XP-E2 R4 1C de-dome using a preferred method (but not in an integrating sphere).

I will use an optical table with linear translation stages and a quality lens mounted in front of each LED, aimed at a backing board @ 5 meters. A manual photo can actually be a fairly good CRI indicator (or at least a good Kelvin temp indicator using known tints for comparison images), using a Nikon camera on a tripod with manual setting to take photos of each LED focused. I have a GW Instek lab power supply to drive each with. Both will be on Noctigons mounted to an aluminum block on the rear stage. Test will be at different comparison amperage levels, power on <10 seconds, photo take, power off, cool time, repeat. This is pretty effective for real-world intensity differences I find. Using OSB wall as the backing, CRI becomes more apparent than using a white wall, as varied colors of wood exist to be rendered inside of the projection image.

The only physical difference between E2 and E2 Torch I believe is E2 has a 2.45mm dome height and Torch has a 2.35mm dome height, but I’m pulling those dimensions from memory, so double check if concerned of them. That is why the divergence angle increases 10° to 125° total on the Torch model. So yes it is slightly physically different than before. I suspect Cree does this angle increase, because a higher current rating is capable of covering more area with similar intensity light—so increase output angle to gain bare-beam coverage.

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I did a test as well :-) let's hope we have similar results. (and welcome to BLF, MEM, it is nice to have another led-tester in the forum, with the bit different test-strategy that you are planning to follow, there's only more insight in the performance of a led !)

I received 6 XP-E2 Torch leds from DBCstm. They are the U5 bin from Mouser (Cree part nr. XPEBTT-01-0000-00Y80), which is the highest bin that Mouser sells and the highest bin according to the datasheet. Why Cree chose the XP-L bin-code (outputs compared at 1050mA) for this led instead of the normal XP bin-code (outputs compared at 350mA) is beyond me! The colour temperature is claimed to be from 6000K to 10,000K (quite a range!), which explains why at least the led I tested does not look all that extremely cool, quite comparable to the XP-E2 R3 1D0 tint from the led I compare it with actually, it must have been closer to 6000K then. First a close look at the leds:

XP-E2 R3 1D0 -><- XP-E2 Torch U5

The package and lay-out looks exactly the same, but the die of the 'Torch' is much rougher/flaky. (the black corner of the Torch led is a marking by me)

I reflowed one of my XP-E2 R3 1D0 leds, and a XP-E2 Torch U5 led on 16mm Noctigons and tested the voltage and led output in my integrating sphere. My methods are explained in detail in the XP-L test thread, with the difference that I used my big integrating sphere instead of the smaller one, but since both are calibrated with the same constant output light source, they should produce the same results.

After testing the leds I dedomed the two leds by heating the boards to reflow temperature on my heat block and then hot-dedome them with a scalpel. I then tested the leds again in the sphere.

The results:

Observations from the graph:

*not only does this XP-E2 Torch led have a (not too dramatic btw) higher output than the tested XP-E2 R3 led, but the maximum output is reached at a bit higher current as well (3.0A as opposed to 2.6A), this is at a higher current than any of the XP-E2 leds that I have tested, none max'ed out at higher than 2.6V. This suggests that the Torch led does not just have a higher output/efficiency, it might also have been structurally changed a bit.

*this Torch led has a maximum output that is 22% more than the led it was tested against, this sounds good, but it might be a bit less promising than it sounds. Comparing the dedomed outputs gives me the opportunity to include four other dedomed XP-E2 R3 1D0 leds that I have recently tested (in the 'cherry-picking' thread). When the best performing led from the five tested is chosen, the Torch does only 14.6% better. And then again, if the XP-E2 bin had been the top R4 instead of the tested R3 bin, that best performing XP-E2 could have been 6% brighter even, and compared with that best performing from the best bin conventional XP-E2 there is only 7.2% improvement leftover that this Torch led provides, this would just be about one bin-number up: R5. (this is not completely fair, I should have 'cherry picked' my Torch led as well for this logic).

*the Torch led has a 0.8V higher voltage than the tested XP-E2 R3 led, but that is within the variation that exists within XP-E2 leds, i.e. the best tested led nr. 3 in the cherry-picking thread is only 0.3V lower than the Torch.

*a general observation: dedoming in these two leds caused a 9.2% and 9.3% decrease in light output resp., with no voltage changes. I tested a XM-L2 T6 3C domed and dedomed a while ago and dedoming caused 9.1% decrease in light output with again no voltage change. These numbers are very consistent while I have heard rumours before of 20% light loss and noticable voltage changes, upon dedoming.

Conclusion

I only tested one 'Torch' led, but it seems like this led is not the led with the dramatically improved surface brightness that I long for. Let's be gentle to Cree and say that it is about 10% brighter than the best bin XP-E2 around already.

On the other hand, I feared for an ugly extreme cool white tint but at least the XP-E2 Torch that I tested had a very bearable tint, not much above 6000K, and dedomed I (me=highCRI-snob) would call the tint actually pleasant :-) So in this perspective, the XP-E2 Torch is a fair upgrade for who wants cool and bright!

Mod

In the XP-E2 cherry picking thread I used the best of four tested dedomed XP-E2 R3 1D0 leds for a Supfire F3 zoomie build, and measured the throw to be 96 klux@1meter. This Torch led should do it a bit better, and because I was modding another F3 for a BLF-member anyway, I could use this led (he will not mind ) and see the improvement in a real flashlight. So I did the exact same mod again (Supfire F3, 6x7135 AK-47-A driver, XP-E2 Torch led, cosmetic blackening of the board mounting ring and led). The driver of the second mod provided 2.07A current, while the first mod did 2.10A (there's some variation in 7135 chips). My measurements say that the led in the first mod at 2.10A produces 452 lumen, the Torch led in the second mod at 2.07A produces 491 lumen, so with the first mod producing 96klux@1meter throw, the second mod should produce 104 klux@1meter.

Well, I measured 107 klux@1meter in the actual flashlight, that is close enough :-)

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Nice :slight_smile: thanks djozz

So this Torch XP-E2 is basically is a flux bin over the R4 bin.

I wish you had also tested at 3A or maybe even 3,5A non steady state from cold, so we could see if we could get a bit more output at start, because it always drop from the temp & volt sag in the batteries anyway in a actual flashlight.

Cool, so you got 491 lumens at 2.07A in the zoomy light with all those inherent losses, almost exactly what was predicted by your steady state chart but that was measure at the led. If i am not reading your chart wrong, i have done that before :wink:

Was the 491 lumens at start or after 30 second? I am just really curious about the differences between measuring at start in a light & measuring at steady state over a longer time :slight_smile:

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No, I'm sorry, but the 491 lumen was the bare led (dedomed). I did not mention the lumen output of the zoomie.... but I just did that for you : zoomed out: 290 lumen, zoomed in 95 lumen (long focal length lenses like in this zoomie give narrow hotspots and big differences between zoomed in and zoomed out)

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Aha! yes now that i read your text again, i see that i had drawn the wrong conclusion :wink: :smiley: thanks

Ok, so the Supfire F3 with the XP-G2 Torch in it gives 104 klux@1meter & 290 lumens zoomed out, right?

Interesting that means it is 39% loss from the bare led measurement.

What is klux? is this the same as the often reported kcd? :~

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Thanks again. I have a few also from the guilty person mentioned. It will be interesting what tint they are. I’ve pm’d you my address so you know where to send your small sphere now that it is gathering dust and taking up precious room. :smiley:

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Mine doesn't look like it is 10,000K, more like 7,500K or so. It looks slightly cooler than most of the 1As.

I also tried pushing one past 3A and the results were underwhelming. I don't think that this LED deserved a new name, as it pretty much performs like a slightly higher binned XP-E2 and can't really handle more current.

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I made a topic of the light loss in this zoomie: http://www.budgetlightforum.com/node/38424

Yes, I personally have never dug into 'kcd' but it is the same number so I never bothered . I always use klux@1meter because that is how I measure it: I measure the klux@5meter and calculate back what it is at 1meter (times 25). klux@1meter is a sort of standard way to represent throw.

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Please use kcd. See https://budgetlightforum.com/t/-/3879

Thanks! :)

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Thanks for the link, I read it with interest. :-)

I will be good, and use kcd from now on. But I still think that using klux@1m, although not the proper unit, is more clear for the reader because it gives a direct clou of how it is measured.

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Thanks. I'm sometimes using "xxx klux@10m = yyy kcd" for clarity.

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I guess that would make you a member of the Klux Klan? J)

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I’m on a mission, just built my 7th Eagle Eye X6 light, another Quad. The “weakest” in my line-up, this one has 4 of these XP-E2 Torch emitters under a Khatod optic that claims 10º. With a 17DD Hybrid S driver and TK’s A6 firmware it’s pulling 8.24A from a Samsung 26F for 1749.15 Lumens.

It’s got a pretty nice hot spot for a quad, but it doesn’t look like what you’d expect from 20º (I think the 10º figure is a half-angle, always deceptive that)

About to try a hotter cell and see what’s shaking with these tiny emitters. I’m assuming they can handle it….

Edit: Oops! Make this my 8th, forgot about building the single XM-L2 U3 1A that does 1811 lumens. :slight_smile: Planning 10 X6 lights that are all different. I have 3 Quads, but each is a different set-up with much different results.

Edit II: OOOPS! Seems like the little XP-E2 Torch and myself are not made for each other. North of 12A one died. A second was injured and limping (dome separation).
So I did what I had to do, I put 4 XP-L V5 1A de-domed under the neat looking Khatod optics. :slight_smile:

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Damn, that kills my plan Dale. I wanted to do a triple E2 torch with a 17DD. Oh well. Parts are already ordered so will just have to see.

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Keep that bit of resistance and you should be fine, or just don’t use the top cells.

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I’m disappointed that you were disappointed with it. I had a glimmer of hope it might make a decent light

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All in all I think they’re ok but can’t take high current. And well, I uh, kinda, uh, maybe run em a little too hard? :bigsmile:

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Haha, I don’t doubt it Dale

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Stick 6A-8A worth of 7135s in there and call it a day! I know that the little XP-E2 torches can handle 3A, but after 2A or so you're not gaining very much.

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I just built a light using this led running at 800 mAh flat knacker without it raising a sweat. Thanks Dale.