No idea, in a T20 the XP-G2 is about 30% higher candela output than an XM-L2 from the dozen I’ve put together. Were they tested in the same host? Your XP-G2 numbers are spot on with what I get with an S2 2B in a T20, so either that’s low on your light considering the S4 2B shows higher output than an S2 2B, or your XM-L2 measured high.
Edit: your XM-L2 number is about 60% higher than I’ve ever measured a direct drive XM-L2 in a T20. I’m betting something is going on with that number.
I wonder……I didn’t use any retainer on the 1505 as I didn’t feel like soldering to the pill when changing out emitters. I wonder if the XP-G2 separated from the pill slightly and the LED was getting heat soaked. Hmmmmm
Ha, no duel. I’m sure you will beat me to 500. I just wanna get to 500 just to say I could and did.
Oh, by the way, did you see the amps for the XP-L V6’s? I think it was you having issues getting the current out of them. I know there is speculation they are really V5’s from LEDDNA, but 1 bin should not cause that huge of a difference should it?
C’mon, this could be fun, let’s push the envelope on these things. Let’s take them as far as we can get them and then swap our final resulting lights. My goal is to beat my K50vn at 575kcd. I’m thinking I can definitely do it with a 1405, but the 1504 should be a nice challenge.
Wow. this is some great info here thanks n10sivern
It has cleared lots of questions i had, but raised some new ones.
For example, please do a full description on how you modded your 1504, i am wondering what low resistance mods you did just to know if you left any performance on the table or not.
I know for example that KKW did not do a switch board bypass & if you did that could explain some % of the lower numbers he got, but he also used the better 6A ebay switch for example, so please do a full write up of the mod host you used & hopfully that could solve some of these questions.
The new XML-2 U4 looks very promising i suspect RMM will see a bunch of more sales from this comparison.
You said you where going to try out running it without a driver like i do, and compare with a DD driver to see how much of max output we lose by using a driver, i hope you still want to try that because i am very curious about the result
If you can get a similar performance increase as KKW got with a home made collar, that XP-G2 S4 458kcd + 20% could get you as high as 540kcd & that is at 30 seconds. Who knows maybe at start it could break 600kcd to do that it would have to voltage & heat sag 12% from start.
I have read many times here at BLF, that warmer emitters generally in the same flux bin most often loses to colder ones.
It can be from the higher phosphor thickness or the not pro level light meters affinity to read colder light higher, or aspheric lights that often seem to get higher readings from colder leds.
Not a 100kcd difference though. I have an S2 2B running at 5 amps in a 1405 that only measures a tad over 400kcd on my meter. That’s the same tint, 2 bins down, at almost 30% more power. It shouldn’t be 55kcd lower than his S4 2B.
As i calculate it thats almost exactly the expected increase of 14% (400kcd +14%=458kcd)from 2 flux bins.
I know you said its at 30% more Amp but, the higher flux bins always seem to need less power/watt to get to max output.
If you check his XP-L V6 (that i believe is a V5) and compare that to the XM-L2 U4, that is also 2 flux bins difference (if i am right about the V5 part) and show a similar lower Amp because of higher Vf but a higher output characteristic.
EDIT, The difference of the XP-L to the XM-L2 U4 is almost exactly 3 full flux bins or 21, that would fit if the XP-L is in the lower scale of its bin & the XM-L2 is in the higher scale of the allowed 7 variation on flux bin steps.
But as you say the only way to be sure is to use the same meter, or that you send him a light to test
The bin by itself would only explain it if they were running at similar power levels as I understand it.
I’m really starting to suspect that I have a meter that reads low, which is a much better situation than my lights all underperforming in a very consistent manner.
I am not sure it works like that, how would you explain the difference i bring up in my EDIT at the previous post then?
I mean the good old XM-L could sometimes pull 8-9A, but that doesn’t mean it would output what a XM-L2 U4 at 4.73A can, the higher flux bins with optimised for efficiency emitters, always seem to pull less amp but output more when running fully DD. They are just converting less of the energy to heat, but unfortunately they also seem to get higher Vf in the process, so they get harder to drive with our battery’s sloping discharge curves at high output for long, in single battery DD driven lights at least.
I guess you can draw some conclusions when you get your XP-G2 S4 from IOS and compare
n10sivern and I have both built XP-L V6 3C versions of the 1504, and his measured much higher than mine there too. I’ll know more once I put one together with an S4 2B.