I was sent two sample emitters that were identified as XM-L2 U3's, but with no tint information, to test for verification they are truly U3's as claimed. The vender rep apparently is having some problems here on BLF and most of his threads have been deleted - BLF Id: bestflashlight, store: www.willbuying.com.
Let me summarize the test procedure:
used a standard, stock Small Sun T08 host to test with because of it's stable low amps (1.95A), 2 parallel cells, amps can be measured by simply jumper'ing across the switch, easy to work with
since the 2 samples came on standard 20mm aluminum MCPCB's, I stayed with that for all comparative testing accept where noted - the last XM-L2 U2 tested is on a Noctigon
measured battery voltage and amps on each run to ensure consistency
used Fujik grease under the star (I got a ton I hardly ever use...)
Results (lumens 1st number is at start, 2nd number is at 30 secs):
Emitter
Source
Lumens (bare in host)
Lumens w/reflector
XM-L U3 1A (14mm star)
Kaidomain
258-241
---
XM-L2 T6 0D (16mm star)
CNQualityGoods
265-258
---
XM-L2 U2 1A (#1)
Kaidomain
255-252
673-656
XM-L2 U2 1A (#2)
Kaidomain
255-248
673-660
XM-L2 U3 ?? (#1) - maybe 1B?
willbuying.com
262-255
680-663
XM-L2 U3 ?? (#2) - maybe 1C?
willbuying.com
248-241
656-642
XM-L2 U2 1C (#1)
IlluminationSupply
272-269
717-704
XM-L2 U2 1C (#2)
IlluminationSupply
272-269
711-694
XM-L2 U2 1A /20mm Noctigon
Intl-Outdoor
286-282
765-758
Notes:
the lumens reads low for the "bare in host" -- probably because the inside of the head is black and side radiating beams are absorbed, however, results are pretty consistent with the reflector #'s
Sorry, didn't measure the XML U3 or the XM-L2 T6 0D with the reflector
Conclusions:
hard to believe the supposed XM-L2 U3's are in fact U3's. They are consistently lower than known good U2's (from IS and IOS). I'm thinking they are T6's.
another scary result is the poor performance of the KD U2 1A's - I don't feel they are true U2's based on these test results. They are probably T6's as well
I didn't expect the IOS U2 1A to do as well as it did. Didn't think a copper star would make much a difference at 2 amps based on Match's and relic's test results. So, what could be going on there? Is a true 1A that much brighter than a 1C? Maybe a better reflow? Didn't check but maybe the LED sits a bit higher getting better reflector #'s but that doesn't explain the better bare #'s.
Thanks for doing those testes Tom E. This certainly deserved its own thread.
This puts Willbuying in the “avoid” group for emitters to me. When that is said. I considered them avoid from the beginning with all their BS.
As you probably have read a few times I have been suspicious to the KD XM-L2 U2 emitters since I first got mine when they just came out. KD have always been full of BS and lies as far as my experience with them goes.
I would say your numbers shows that KD are not trustworthy either… With so many other sources for emitters that are better, I see no reason why people should give their money to KD or Willbuying.
I was testing my uf x6s yesterday with a ft t6 1b on an aluminum sinkpad. Was really bright according to my ceiling bound. Decided to swap in a kd u2 on noctigon.
It was me, but after some requested I deleted edited my post, some people believed I was only pointing out to them how to fake the label correctly by showing where they failed.
Nice work Tom E! Great comparison, really helps when deciding where to buy emitters from.
You are right on with the evaluation of a bare host with no reflector. A lot of lumens get eaten by the black interior of the host.
Did you get any emitters from convoy-flashlight? I’d be interested in seeing a comparison to them, as Simon does have decent prices on a few unique tint emitters.
Great info and thanks. Too bad about KD, that’s a shame.
As for blackballing willbuying I doubt I will. I can’t say if they were purposely lying or simply are clueless and got taken in. They seem rather clueless if you ask me. They might very well have been sold a “bill of goods” as they say. When I first started buying flashlights I would have blackballed any seller who lied to me. Unfortunately that would so severely restrict who I buy from that it’s not worth it. Other than the “all things being equal” scenario where I can reward the better sellers, I will continue to buy from whoever gives me the best deal on some items. But on anything where quality matters then you have to go with a company that you can trust. I know that international outdoors will continue to get by emitter business. Actually with the last sale they had on U2’s on octogons it was the best deal and the highest quality.
hikelite it was me that requested you not pointing out how to better fake the labels, sorry if you felt I was getting at you, I truly wasn’t, I just dont see the point in telling people how to do a better job of faking something like that, much as me being a petrol head, I don’t like seeing info posted on how to break into a car easily etc.
Tom, thanks for clearing up some things we were already suspicious of, it would have been nice to have been suprised but the results just confirm what we were already thinking.
Have you had a chance to play with the hi cri emitters from is or ios yet? I just got my x3 today and I love the 6a1 tint, can’t wait to fit the other emitters I ordered in my edc’s now, should be absolutely ideal for my work.
The x3 has confirmed for me the direction my defiant 3c is going in, I think the tint of the high cri emitters, along with the feel of a 3c based light will be awesome as an old school feeling incan analogue, so that’s how I’m going to build mine. Ld-3c driver (assuming ohaya’s findings on that driver prove to be just one bad example) 3a to the emitter, hi cri xm-l2 emitter, with the bored body tube and a cunning spacer design, I’m hoping to be able to run 1*18650/26650 2*18650/26650 or 3c.
Sorry for the thread derailment. ……carry on. :bigsmile:
I’ve fot some of those from IS. While they are XML2 for sure, I did not notice much difference in my Apex 5 before when it had xml t6 and now. It is probably because to my eye those are closer to NW than CW.
What I think is interesting is the very consistent result I saw on the same emitters from the same batch/vendor (U2 1A's from KD, U2 1C's from IS). Of course the KD's are not really U2 1A's but they are consistently bad .
What I wanted to do was run a series of tests for high current on copper which is more realistic for my use/builds, but I saw merit in keeping the amps consistent and low so resistances and possibly poor reflows and other issues may not be as much a factor.
It was also interesting the XML U3 had the biggest drop over 30 secs, maybe because of the 14mm star, maybe because it's an XML. Would have liked to tried more XML U3's and XM-L2 T6's from different vendors. XML U3's should do about the same as XM-L2 T6's according to the chart here: http://flashlightwiki.com/Cree.
Also I didn't include these results, but I tested the original stock XML T6, and a supposed XML U2 1B pulled from a Convoy M1 and the results were the same. I wasn't 100% certain though the U2 was a U2, so didn't include the test results.
I’ve noticed a lot of variation in aluminum dielectric stars regarding thermal performance. Some are better, some are worse. All are not as good as direct-bonded, but the variation can really throw off tests like this. I believe it has to do with the dielectric thickness and materials used. I have not done thorough testing on it, just from experiences with different stars in lights I get.
You’ll usually notice it as a very quick sag during the first two or three seconds of power on.
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