I do have an old XM-L but would hate to do the swap. Do these XM-L2 U3's have really high vF? Like 4.2v at 4A or something?
Tried the beam out my backdoor now that it's dark. It's pretty impressive, more so than I expected. Can't get to a better test location right now due to all the snow.
I wonder if I should try bridging the sense resistor?
-Garry
Here’s a couple of threads talking about the higher vF of recently purchased emitters.
Yes, the beam seems a little underwhelming indoors, but when you get it out to stretch it’s legs… 
Thanks for the links. This is my first dedomed light.
-Garry
Quick question…
I have both of these LEDs ready to dedome and put in the Courui with a fet driver and copper heatsink, which one would you choose? I want best balance of CW tint, throw and output.
XM-L2 U3 1A 20mm Noctigon
XP-L V6 1A 20mm Sinkpad
TBH, I don’t think you’ll end up with a true cool white with either, after the de-dome.
I know it may vary somewhat, but from the few I’ve done, I’ll bet the XM will be cooler, but might lean to the green side, & the XP will will be a little warmer, & tend to the yellow side.
of course, YMMV.
Do both, let us know the outcome.
If I where you i would chose the XP-L V6 1A dedome.
I did that in a DD Zeusray a while ago, the new XM-L2 U3 are almost impossible to get much over 5 amp, the XP-L can go to around 7A in a DD or MOSFET driven light with a strong high discharge battery + fully low resistance mods.
The amp estimated is for led’s with the dome on, i think you lose some of the top amp & lumens with a dedome, but the XP-L are said to lose less.
I liked the XP-L V6 1A’s tint after the dedome, more than the CW xm-l2 i have done before, non of that sickly green hue :Sp , but a yellowish NW but still CW tint, especially at distance it look more CW than close up.
Where can I get a replacement lens for my courui? Mine came today and it was in two pieces. 
I won’t even bother contacting GB because the light itself took like 2 months to get here.
There’s a UCLp from flashlightlens.com at 73mm x 2.25mm. The stock glass is 72mm x 2mm, will it fit?
The dedomed XM-L2 U3 1A can throw pretty well but the tint is too green for my taste. I will replace it with a XP-L V6 1A in a couple days.
I think that’s the one Dale has used with good results.
I have several camera filter lenses on their way to me on the ‘slow boat’ to test in a few throwers, & will post before & after results when I get the chance.
@will34, please try to measure somehow the difference in throw between the XM-L2 U3 1A & XP-L V6 1A.
Any detail would be very interesting, as far as i know from here no one have tested & reported on that yet.
My guess is that the XP-L should throw better because it can be driven harder & with more amp & and therefore should throw longer.
I have just been debating this in the Zeusray thread check out near the end, it hope you can add some insight in to any possible differences between the two options.
Ok I took my first lux reading ever last night and calculated throw at 118kcd. This is with my dedomed XM-L2 U3 1A driven by (3) fully charged LG 4.35v cells with stock driver resistor modded for near direct drive performance (I measured 3.05A input current). My emitter is up into the reflector as far as it will go and focus looks best at that point. My meter is the HS1010 cheapie. I was measuring "472" on the "x10" range at 5 meters. Seems a bit low to me, but the light is really performing well! What are others seeing with dedomed XM-L2's?
-Garry
I agree it seems a bit low. Two things I would do before messing with the focus, confirm the batteries in your meter are fully charged and take you measurements from a longer distance. I measure my throwers at 9 meters, if I had more room I’d go out a bit farther.
For reference my stock D01 measured 77.3kCd stock and 82.9kCd after resistance mods, both converted from 9 meters using an HS1010A. That was with the driver you’re using now in stock trim and the dome on.
The batteries were the "heavy duty" ones that came with the meter and were never used until last night, but I'll try some fresh alkalines. I did this in my basement, so I'm limited how far I can go. I might be able to backup to 7 meters.
-Garry
Something’s amiss if you are only measuring ~3A. Do you have any high-drain cells to compare with?
Even with the newer emitters you should be getting more than that.
I picked up one LG high drain cell. I'll have to charge it up though. I don't see why I need a high drain cell though. Even 2 reg cells should push 5 to 6 amps - especially 4.35v cells. Maybe it's an issue remaining from when I shorted the reflector across the emitter wires.
-Garry
Nightbird95 measured 3.62 Amps reading at the tail cap with batteries @ 4.13 volts, with the same mods as I, although he didn't say what battery he was using.
I know I measured just over 4.5A from my setup with a fully charged 25R, with resistor bridged; The same cell, thrown into my A60 w/Nanjg-105 fet modded driver pulls ~5.5amps.
Even though it's a FET based driver, I wouldn't be expecting big output like we are getting from the BLF-DD type FET drivers. 5-6 amps isn't going to happen with the stock Courui driver.
I managed to have a few minutes last night to take another lux reading, this time at 20 feet (6.096 meters). I measured 3340 lux which calculates to 124kcd. I was slowly moving the light around to check for the highest reading and it was really "touchy" as if the highest reading is only from the exact center of the beam. A millimeter of movement and the reading dropped significantly. (I suppose this is normal, especially with a dedomed emitter.) I did not try other batteries in the meter; If I get chance I will and also try measuring at 24 feet (longest I can do in my basement).
Charging up my high drain cell now for current measurement tonight.
-Garry
Will be interesting to get an Amp reading from the high-drain cell.
Sorry if I missed it somewhere, but what exactly are the “leica m39 m42 adapter” being used for?
I used it to lock down the pill tightly to the "step" it rests on. Stock the pill is loose. I'll try to upload a pic shortly. EDIT - sorry, pic I won't have access to the pic until tomorrow morning. I thought it was still on my phone. Basically, you thread in the pill all the way then thread that ring in against the pill.
-Garry
Here -
Thanks to Go0se, I went down this path. Didn’t have to worry about threads.