Got my green D4 (219C) last night. The user interface is as nice as everone else says, and so is the heating up 
Wanted to hotrod it further with XP-L2’s but changed my mind, I like it better with 219C SW353 R9050 leds.
And now I want another one for the XP-L2 mod :person_facepalming:
Played a bit with thermal regulation.
It’s less smooth than I expected, the output stays visually stable, makes a jump, stays stable for another while, jumps again etc.
Also, I noticed that if I heat it up a bit, turn it off and start at full output, the peak temperature will be much higher than originally. Also, I think it may be exceeding the level that I configured….or maybe my burnt fingers got more sensitive 
If you set the temperature by switching the light off when you feel the max temperature has reached, then the actual temperature at the sensor (inside flashlight) is higher, as there is a temperature difference, or “delay” with the surface. So from a cold light when you engage turbo, then the max temperature you feel should be similar, but when you go to turbo from a warm light, then the max temperature you feel should be higher. This holds true for steady state max output/temperature at about 600-ish lumens as well; this temperature will be higher than what you think you have set.
At least this is my take on it.
Edit:
The higher the temperature increase rate (dT/dt), the bigger the difference between desired maximum temperature (what you felt), and actual max temperature value (Tmax set by D4).
General note: I find blinking very bright. Even during the day it can hurt the eyes.
I guess you’re right. Idea for future improvement: Do the calibration twice to make sure it starts with a warm light. Or do it with far less than 100% output, so the effective delay is lower.
What’s the recommended way of adding GITD to this light?
Has anyone found a matching GITD o-ring? How about a glow paint?
A word of warning. Just noticed there was a 6.3mm metal shaving peeling off the positive end of my 18350 tube. Gladly noticed it before sticking in a battery. It was sticking inwards a bit so could have possibly shorted the plus and minus, since it was longer than the distance between contacts on the driver end (3mm).
My 18350 tube had that too, maukka, the shaving forms where the threading ends. I did not think much of it, just pulled it off, but you are right, there is a possibility of things going wrong if you are not observative and unlucky.
This killed Lexel’s Klarus G35 driver for the review or not? [Review] Klarus G35 supplied by Banggood, partially review as I killed the driver
Ok, it wasn’t a piece of metal from the Emisar D4, but from the G35 I presume, hehe. 
Buy a sheet of gitd foil. Then you can cut two stripes around 3mm wide and stick them around the inside of the light. There are two flat walls where you can stick them to.
TK yes he is screwed.
He needs also a soda can light.
Fuzzylogic have checked out the Q8 thread?
Just a pic to compare it to the S42. The D4 is superior in all aspects but one: USB charging.
But that is quite a big one for me though, a future version of the D4 with USB charging (and regulated maximum modes that temper those modern low Vf emitters a bit) certainly would be an improvement for me, even if that adds a few mm of length.
@djozz
it seems the S42 could be as short as the D4. There is a long tripod thread in the tail of the S42
I know, and the driver with USB socket and components probably eats extra mm’s too.
Got a link for the gitd foil?
I used this https://www.ebay.de/itm/141654400313
But I think you can find something similar in your country.
Thanks.
Mine showed up 2 days ago… I can’t put it down since then !
219C and grey, I just added a Convoy clip (slightly re-bended to fit)
How is the tint on the xpl-hi 3a.I got the nicha 219c version and was thinking about getting the xpl-hi mcpcb from international and trying it.I figured for about the same price as and xpl-hi i could have the light and 2 different mcpcb.
Never used or heard of GITD Foil, but I use this Products - Glow-On and it’s pretty impressive!
Th adhesive vinyl works best, it last about 8-12 hrs, at about the out put level of a trit, the paint (water based) not as long but is good for filling in the back ground of the board, but it is a PITA to use, I have bags of the powder too that I mix with petroleum/epoxy based paints, it applies easier if you thin it out.
On these smaller lights I just stick with the vinyl tape. I have a precision shim punch and knock out some different size dot’s to stick dead center of the triple and quad boards, then use a razor and straight edge to make strips, to run around the ID of the head or small strips just at the top or bottom of the LED’s or to make locator strips around the battery tube or head of the lights.