U3 stars different tints? NOW with pix!

Ok - I bought 4 kits in pieces to build 18650 tube lights with. This host, U3 1B emitters, and Nanjg 2.8A to reprogram. So, 3 lights assembled and tested, 2 are definitely more cool/white, one is more neutral, maybe little more neutral then the 1C's I have. In measured brightness, 1 of the more cool tints is definitely better measured 799 lumens at 30 secs, while the other 2 measured 758 lumens at 30 secs. So the difference is about 5%, but figure you get maybe 4-5% on putting in an AR lens over a stock lens, so 4-5% is fairly significant, I feel. Measured amps and batteries were all the same as well. Switching around batteries I got the same results.

This, to me, is definitely bothersome - I haven't seen this much variation in rated tints before. I've done a lot of U3 1C upgrades, and they all seem to have very close to the same tint color in the wall beam shots. I know in theory, emitters in the same tint level can have a lot of variance, and brightness can vary as well.

Right now, of course, FastTech seems to have the best deals on these emitters and drivers. The qty breaks starting at 3 is excellent, besides the fast shipping, no charge shipping, etc. the EDC lights I put together for $14 is unbelievable in quality and performance when you think about it - 760 lumens, U3 emitter, custom programmed driver in a regulated driver. However, the issue with these emitters is bothersome - I hate the fact there is no way to verify what the heck this CREE XML emitter really is, but that's always been true.

Dubious binning is a possible culprit here. While there can be a tint shift at different current levels, I doubt that's what at play here.

>>>>>>can you take a photo of each emitter and a t6 cool white to compare?

Just need the time. I’ll see if I can set something up later.

Like I asked before, has anyone seen a refllector change the tint? Doesn’t seem probable to me, but what do I know?

>>>>>>>>> 2 are definitely more cool/white, one is more neutral, maybe little more neutral then the 1C’s I have

So far the 20mm stars are one tint and the 16mm stars are another tint. That seems a little suspicious, suspicious of what I don’t know.

I should have said at the outset that I bear NO GRUDGE +NONE toward fasttech. I think they are the best vendor going for this type of stuff: lights and accessories. If I had to guess from the few fasttech issues we have seen so far here on BLF …… Fasttech has the same issues with chinese vendors as we do, mostly ones of quality control. They sort of have to trust vendors on some things until proven wrong.

I’ll try to find the time later to do a tint line up. I have an ultrafire C8 and a fandyfire that have “U2” printed on the light. This supposedly u3 emitter looks remarkably like the tint of those U2 lights, although who knows if those really have U2s in them.

Different reflector styles can influence tint, especially with the tint ‘gradient’/separation issue that affects the XM-L (much more so than say, the XP-G).

In your case, different reflectors are likely not the issue. 1B tint bin spans ~500k, and white-ish to blue/green-ish hues in different corners.

What am I saying? Lights take precedence over work. Here is the pic:

Okay, lost the first version of this, so lets try it again. Urggh.

From left,

1. Xin stock C8

2. No name C8 with a U3 1B fasttech 20mm star

3. Uniquefire C10 with a 16mm U3 fasttech 1b star

4. Stock Ultrafire C8 from Fasttech that says “xm-L U2” on the battery tube (whether it really is a u2 is anyone’s guess).

To me, number 3’s tint looks suspiciously like the tint of 4. It does not look like the tint of number 2.

Both stars came in the same fasttech order. Only diff is that one U3 is on a 16mm star (warm one) and the cooler one is on a 20mm star.

Can tints really vary this much. Are these really u3 emitters?

Both “U3” emitters are definitely brighter than the original T6s that were in the original stock lights by maybe 10-20%. The two C8s that received the upgrade were my dimmest C8s. Now they are equal to — or surpass — the brightest C8s in my collection. So they have to be brighter emitter than a T6. I don’t think a U2 would make that much difference over a T6, but waht do I know?

Thanks for any comments you have.

My first beam shots, so go easy boys.

I think those could both very well be u3s… Just extremes in the tint bin corners… What do some other members think?

That's what I'm thinking - probaby really U3's, just variance in tints, which is what I got in my FastTech U3's. U2's are/were also in 1A, 1B and 1C, so I generally see something like the 3rd or 4th beam pattern from U3 1C's - more neutral than typical T6's but not as neutral as a 3C.

if you really want to be sure what you’re getting, just pay a little extra and get the LEDs from Illumination Supply and reflow them onto your own boards. It’s not hard and you wouldn’t be left scratching your heads trying to figure out what’s going on. The XM-L2 T6 3C from IS have a beautiful tint, not yellow, green or blue, just white (albeit a little warmer than cool white)

I bought a bunch of bare LED's from IS, the problem is he doesn't have what I want. I'd order 12 XM-L2 U2 1C's from him if he had them in stock. I'd also order XM-L U3 1C's but I've never seen them listed at IS. His prices are pretty good on emitters, shipping costs add to it, but it's great when you get them quick. FastTech is a complete product line shop, so I can order all the parts I need in one place, so if I'm ordering, drivers, hosts, lights, springs, centering pieces, tailcap buttons, etc., might as well order the emitters and save a few bucks because the rest of the parts I need are coming from HK anyway, no need to rush the emitters.

I’ve noticed that the reflector has a subtle impact on tint. Some reflectors cool the output a little. I’ haven’t been able to quantify this, but I suspect that the best way to compare emitter tints is bare emitter on a star on a heat sink, same drive current, shining on the same surface. Use a separator to prevent overlap of the light shining on the surface.
To prove (or disprove) that a reflector affects tine, use the same emitter, same drive current on a large heat sink (temperature affects tint slightly) and hold the reflectors in front to compare tints.
Too many tests to do… so little time to do them.

he has them listed
https://illuminationsupply.com/cree-xml2-bare-u2-1c-tint-6500k-p-279.html
although I don’t know about stock. If he had them, I’m sure he’ll get them again, just ask him. He’s a very friendly and helpful guy. XM-L U3 seem very limited, I’ve only every seen them at Cutters. Personally, I wouldn’t believe that the “U3” from Chinese vendors really are such (apart from perhaps Intl.Outdoors), they’re most likely just U2s.

I don’t have a problem with Fasttech at all, I just decided after previous experiences with LED tints to go for someone I can trust.

In fact, I have that exact host on order, along with a 6x AMC7135 board, for a XM-L2 T5 3C I got from IS. How did you find the build and quality of the host? How’s the heat dissipation and the beam? I might keep it OP or I might put a TIR optic in there if one fits, I’ll have to see.

I did email Craig - XM-L2 U2's coming in early April. I've ordered U3's from a couple of places besides FastTech (maybe I-O as one, not sure of other), been using them for months now. That host from FastTech is actually pretty good for $6 and change - brass pill of decent size. I did add a centering plastic piece on the emitter, and added a thin o-ring inside the tailcap button so it tailstands flat, but overall quality was pretty good and like the beam pattern - more flood style maybe, and also got good output, ranging from 760 to 800 lumens with 2.8A Nanjg. Think the black XIAOZHI style host from CNQ for $8 and change is a bit better with it's more aggressive styling, but that host has it's issues as well with the tailcap assembly. Actually I got a XIAOZHI w/XM-L2 T6 neutral and it's real nice - about 760 lumens as well, and just ordered one bare host from CNQ.

Well, whatever these emitters may be, they are substantially brighter than the T6s they are replacing. If you can solder, I heartily recommend you try a couple. I was going to wait for XML-2s, but who knows how long that will be.

Did another 20mm U3 last night, replacing a T6 in a lack-luster ke-5 copy. The emitter change turned this meh light into one of my best throwers. If I had to guess, I would say that the increase was in the range of 20%. I mean this is SUBSTANTIALLY brighter. Like the other 20mm U3, this one has a cool tint and kicks you-know-what. Man, I was totally surprised.

I suspect that the original T6 was another bottom-of-the-bin bin T6, so YMMV, but maybe not. What a difference. Of course, I do not have another unaltered ke-5 clone, so I can’t compare ’em side by side.

I am eying another sub-performer for a 16mm u3. If that one works, I will try one in a real ke-5. If these so improve iffy lights, putting one in a great light should be stellar.

I also noticed that the U3s seem to run hotter than the T6s they replace, but not by much, but enough to notice. Then again, maybe I am just putting the stars in correctly when the T6s weren’t seated right (one had no thermal compound).

Thanks to everyone who contributed to this thread. I am thinking of doing the reflowing route. I so would just rather buy the starred emitters rather than taking on yet-another DIY project. But just like everything else from China, who knows what you will really get. (+NO+ complaint about fasttech. I know they are dependant on their suppliers.)

oh ok, fair enough :slight_smile: I know that he said it was hard to get specific tints as opposed to broader codes (like the E3 code which is 3A-D), perhaps that has something to do with it.

thanks for the feedback on the host. I was after something relatively small and unobtrusive, so simple is good for me. It’s also more of an around the house+yard light, so throw isn’t that much of an issue.

Okay, I installed another 16mm U3, for a total of 2 20mm U3s and 2 16mm U3s. This U3 is consistent with 2 others; one of the 4 is kinda warmish, almost orangey. But that’s the only one. The others are all cool and BRIGHT!!!

This most-recent one updated a TACTICOOL (been waiting to use that word) uniquefire uf-2220, I didn’t notice until I finsihed that it supposedly had a U2 in it already. Ooops. But it is still brighter, so I don’t see how these can be anything but U3 emitters.

I matched the output on this light to the output on a no-name meritline C8 BEFORE the U3 upgrade, for the purpose of later comparisons. In other words, the 2220 output matched this C8 output in brightness. With a new U3, the uf-2220 now beats the meritline c8 hands down, so these U3s really are a worthwhile upgrade for T6s.

Of course, I did these U3 upgrades just in time for the new better XML-2 emitters to start showing up on BLF, literally today. Figures. Story of my life. Time it perfectly so that I buy something EXACTLY when a better alternative shows up.

Errrgggghh. Oh well. Have plenty of soldering practice now for the XML-2s!

But the U3 prices are good, and the product is super. Fasttech comes through again!

Where are XM-L2's today/ The T6's or U2? Did I miss something?

Oh - I'm also very happy with the FastTech U3's overall - great price, great increase - I did XM-L2 U2/SinkPAD and U3 1B-1C/SinkPAD upgrades and really not much difference.

>>>>>Where are XM-L2’s today/ The T6’s or U2? Did I miss something?

[quote=Ubehebe]
>>>>>Where are XM-L2’s today/ The T6’s or U2? Did I miss something? https://budgetlightforum.com/t/-/16542
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Ohh - thanks! Ordered 3 from KD. By the time they arrive, things are gonna be different once again I bet... Cost is up there but will probably come down. I'd love an XM-L2 U3 1A/1B/1C...

While it is not obvious to measure the bins of leds inside lights, I can’t believe that no one ever considers that the stock budget lights come with xml’s that are just not t6 bins but lower. As I understand companies buy leds on reels with a mixture of bins. Guess where the lower than t6 bins end up eventually? Have you ever seen a light with a cool white xml t3 listed anywhere? Not that have any inside information…

While I don’t think Cree manufactures a T3 XM-L in chromaticity bins cooler than 4000k, I agree with what you’re saying. I assume that budget manufacturers skimp on design aspects when nobody’s looking, so the case of LEDs is a prime example; one simply can’t verify flux bin of an XM-L by looking at it.