When I have collected enough motivation to go on with this, and I have bought two cool white (2C or 1A) XM-L2 leds, I could go for a petrol/hot dedome comparison. For the moment I want to do some mods again.
The texture of the XP-L die and the XM-L2 die/phosfor looks the same to me (yellow fine grainy stuff), just the 3C die has a thicker layer.
Thank you for the followup. I understand about needing to give this project a rest. You sure gave us a lot of good info to digest in the meantime.
Thanks again so much for this great contribution.
Thanks all for the kind replies, guys!
:start small rant:
I posted the first XP-L test also on CPF, and was cross-examined if what I was posting was real, that I had the wrong control led, and why should they trust a home made integrating sphere. All the arguments were valid in principle and I tried to answer the questions as well as I could, it took me a lot of effort, felt that I had to choose the words with a lot of care not to leave a wrong impression . There were however two things that bothered me: 1) all the arguments were theoretical, nothing wrong with theory but it would be so nice if also some people who were actually going to use the led found the post interesting, and responded, 2) there were two people who actually discussed the results and did not go straight into criticisizing the used methods and those were people who also post regularly on BLF (leaftye and Phantom23), perhaps because they had read more about the background of my testing over here, but I think it is not just that.
The thing is that I like posting here at BLF because my work is accepted as is, even if it is not perfect, and people just use the part that they find useful. And I can always count on some nice replies, with appreciation of the work. (I try to do that for other people's work too, but I regularly miss fine informative posts :-( ). I am now not going to post the further tests on the XP-L and these dedome tests on CPF because it will be another time-consuming effort just explaining the limitations and flaws of the tests (that I am perfectly aware of) and not also positively discussing the things that actually can be learned from them.
:end of small rant: (not meant to start another epic crusade on CPF (CPF has good sides too!), please don't start that, it was just something I had to say)
I agree with you, who would want to post data for people who seem to on a mission to discredit you just because you had the audacity to share with them, i like lots of accurate data, and of course we are not wealthy enough to own professional equipment but if we can do the next best thing that is accurate enough and reproducible and acknowledge its limitations but use it to its full potential then in my opinion we would be fools not to do so, and i really appreciate your data because we can ask questions and you answer them and are willing to make improvements and additional tests if we come up with any.
I should buy you one of these: http://www.cafepress.com/mf/24133286/cpf-oval_sticker?productId=196692238 
I dunno - they are very nice and sweet to vinh...
If I could point to one single person that has impacted our hobby the most, I would have to say djozz. Your crash testing showed us the potential of various emitters. We, and others, than built accordingly and began pushing to new levels that were not reached before. We started pushing drivers, hosts, etc. It's hard to quantify how much has changed as a result of your testing. I bet it is way more than you or any of us realize.
And, your work is the most precise we have here at BLF. Anyone that criticizes you here would need to put their money and time where their mouth is and show us better.
+1 totally... Hhmm - comfy had my top vote, but djozz is wayyy up there, very close for sure. Following in the footsteps of Match, Relic38, etc.
Unless the red ink is the blood of starving children I don’t think she would find them appetizing…
Love you guys, but let’s call it a day on the CPF stuff, no matter how well intentioned? djozz did say that he was just venting and didn’t want to start anything!
As usual Djozz your work your doing is outstanding. I don't see a lot of other people throwing there own money away with info like this. Keep it up and thanks.
I have to agree with the others, your work here is well received and the information gleaned used daily. I refer to your crash testing on a regular basis and trust it by putting my money where your mouth is. 
Just put an MT-G2 in a Courui big head. I used 6 of the little Efest Purple 18350’s. It ran a lumens test at 4483 OTF then a lux test of 92.75Kcd and THEN I tested the amperage at 13.84A! There’s some real world verification for you :bigsmile:
I’ve toned it down through firmware as the above was just too much, but I wouldn’t have dared try it that way in the first place without your exhaustive testing. Thank You!
I used to sing silly made up songs to my kids, and here’s a bit of one that I coined off a known old saying. “You can lead a horse to water, but you cannot make him drink. You can send a kid to college, but you cannot make him think….”
Now, sometimes people think TOO much…trusting the books to lead they’re lives. We also have to get out and DO! Thanks for being one of those, the guy that gets it done and then helps the rest of us with some direction. Awesome work!
I just got through reading this thread and yet again I am amazed by the quality information that is shared here among members. Thank you djozz! Your efforts are greatly appreciated.
DBCStm: I agree with you that there has got to be balance between theoretical and applied learning. If you rely too much on either you will have a hard time progressing. Most real scientists/engineers can appreciate this. You run the calculations, do the drawings, but at the end of the day the results you see in the lab are what really count--you often find out that that there were a lot of false assumptions, unaccounted for variables, or other errors in your calculations. Then you get to go back to the drawing board and attempt to explain why everything turned out different than what you had expected!
Ima4wheeler. yes, yes, yes, we do see wider than tall. I want more info.
I haven’t seen a tir that has correct ratio or efficiency. Never a wide reflector. Could build hammer head light, but not so practical for worn lighting (wrist or headlamps). Correction, I did buy a High definition Cree Brinkman in 2009 that had perfect beam pattern, however the efficiency through the tir was horrid.
I have a perfectly distrubuted circulars beam lights, but they waste lumens by pushing light too far up& down in beam pattern: I suspect humans prefer 4:3 screen size and NOT by modern 16:9 (which is technically the actual human ratio.)
IMa4wheeler wrote: This may be a big flop, but I really want to try to use 2 XP-L’s in a TeePee or “V” formation. Hoping it will give a bigger hotspot than an XML, but more intense than and MT-G2 (and hopefully than xml too). The TeePee or “V” formation will help bring the 2 emitter’s dies closer together. It well also aim the most intense portion of the emitted light at the reflector (which is were most throw comes from). The positive contact pad of one will be in contact of the negative contact of the other for a 2S electrical formation. Might be able to file off small bit of the substrate edge to bring them ever closer together.
It might also have a some what elliptical beam pattern, which is a bonus for me as we see wider horizontally than vertically.
Djozz,
It would be neat if you used your remaining emitter to do a dedome test.
Wish I had more info. I still haven't tired this idea yet. It may do what I hope or may just make an ugly beam.
Basically, the emitters will be next to each other. But instead of parallel on a flat surface, they will be at some angle to each other. 90 degrees max. Having the joint between the 2 emitters high (like a Tepee) will create a thermal challenge at high currents, but seems like it would waste less of the lumen output.
Just plan on using a normal reflector. The bigger the better as this idea is for more throw.
Thank you for asking degarb. :)
Like in post #38 (and related post #50) ?
As I understand it, one of the primary contributing factors to produce throw is a nice pinpoint light source. When everyone started going to the big XM-L footprint it was a challenge to get throw out of em. Then the monster MT-G2 came out and the issue there is all the tiny dies, no single light source to concentrate focus on. It’s very difficult to get the big emitter to throw worth a hoot with all those little dies in there. And that’s probably what you’re going to run into with the 3 die process, getting the 3 dies to focus light in one reflector. You’ll probably have a hole in the middle and a lot of artifacts.
I don’t discourage you trying it though, and would like to see what the results are. But the theories I’ve seen discussed all indicate it’s just not gonna happen. Floody, yeah. Throwy, probably not.
djozz wrote:degarb wrote:Djozz, It would be neat if you used your remaining emitter to do a dedome test.Like in post #38 (and related post #50) ?
degarb was quoting me from Post 28.
I see now. I misread it as well. Sometimes those broken quotes are very confusing.
We’ve seen the XP-L meeting the XM-L2 in terms of output almost exactly…but when thinking of using the XP-L in a triple or quad set-up can we count on lower heat at less than maximum current?
If the max is rated at 3A, what kind of efficiency will it be doing at around 1.5A? Thinking that 4 XP-L’s at 1.5A should yield around 2400 lumens out the front after losses. Would they also be making enough less heat to warrant their use at those levels? Or does it end up being 6A burned regardless, thereby similar heat to 3 XP-G2’s at 2A each? The XP-G2’s could only be counted on for an approximate 1700 lumens for that same 6A of current, so would it be a win on the quad set up with the XP-L?
Another way to say it, given equal heat output, what current would the XP-L Quad be running when compared to a Triple XP-G2 set-up?
Seems to me that 2A to an XP-G2 is half an amp over max recommendation, while 1.5A to the XP-L is half the recommended max…making the XP-L in a much more efficient range of operation.
Can anyone confer with this line of thought? Or am I way off base?
Dale, I don't think you're way off base at all. I think that to produce the same amount of lumens, say 1700 lumens like your example, 4 XP-Ls will do it more efficiency (lumens/watt output) than 3 XP-G2s pushed hard. However, that efficiency comes at a cost of peak die intensity, which is what affects throw the most besides the reflector arrangement.
So for a pure efficient flooder, more emitters run at lower levels is much more efficient than less emitters pushed harder. But in a thrower or to increase throw in the same lens/reflector setup, you want to push those little dies to be as bright as possible, even at the cost of peak efficiency.