Try getting the measurement at 10-20m.

I agree, a C8 with a well-focused 2mm2 White Flat at 8A could reach 200 kcd.

I do not honestly know how well focused is the emitter in my C8S. I lowered the reflector gasket quite a bit, until the 5050 square gap surrounding centerpiece eroded and dissapeared. Did I go too far?

If I recall it right the gasket was of this type: http://kaidomain.com/Flashlight-DIY-and-Tools/Misc-Parts/S024676-10mm-D-x-0_9mm-T-White-Plastic-Insulation-Gaskets-for-Cree-XM-L-10-pcs

Concerning the M1 (@ 4.75A), it scores above 100Kcd cold start so that must be right, the M1 reflector surface looks to be about half of a C8. And its surface finish looks of higher quality (versus C8S).

I used the smaller sibling of those gaskets, the XP-L version, on my CSLNM1.TG C8+ with 7mm bottom hole reflector. I sanded down the lip where the reflector rests on to about 0.5mm and it’s perfect. I could just about spot cattle and cattle herders at 600m away this weekend. I could see them moving on the hill. So I know it really performs well.

My previous gasket attempt was sanded down to about 0.2mm and it was worse. Looks like 0.5-0.6mm is a sweet spot.

Thanks KevinZA1988, I think you answered my question. I went too far.


It shows in the hotspot if you are good, the NM1 in a quality smooth reflector (C8 reflectors are usually good) makes a very well defined evenly illuminated hotspot. Slightly off and everything goes assymmetrical and/or fuzzy.


I see that Mouser now has White 1 and White 2 in stock.
May be slightly cheaper than L4P for those in the USA but unknown bin…

I could of sworn I read earlier in this thread that the new 1mm 4040 CULNM can be reflowed onto a XP mcpcb 3535? Before I attempt another reflow and heat this poor led up for the 3rd time can somone confirm 3535 mcpcb’s works?

Here’s the catch: not every 3535 board has the exact same solder pad dimensions. Reflowing 4040 leds works reasonably well on boards with electrical pads that are a bit thinner and thus wider apart. The amount of solder must be fairly precise too, and make sure you position the led very very well!
But yes, confirmed, I succesfully soldered the 4040 CULM on the stock 3535 board of a Micro-GT and have a working flashlight.

Nice, awsome and thank you. YOU DA MAN!! So excited, it’s going into a 126mm aspherical lens super short FL, pre lens w/collaniator and a small waiven collar.

126mm aspheric? Is this a home made job?

I purchased two of the CULNM1.TG leds a while back from L4P and only today had some free time to reflow one for testing but one of them has this thing that is looking like some defect around the die, is this normal for this led or not? I hope it does not have impact on performance or lifespan of the led. :smiley:

I've seen that partial circle "trench" on many white flats1/2, it seems it's from some kind of tool/mold which protects die during pouring "white stuff" over package surface, it shouldn't have any influence on performance.

Ah, it seems like its not a big deal then, cool.

I just threw this led in a C8, driven at only 4.85A, centering was very easy but height of the reflector will be an issue, at the moment i have the same centering gasket i had for the black flat but it turns out this led wants the reflector a bit higher than the black flat, i think that it will need similar height of the reflector as the xp-g2.

Will test all this when it gets dark outside :smiley:

It all depends on eachother, the thickness of different Mcpcb’s will differ , which allows more or less space in the head and that will affect the allowable thickness of the spacer and your focus, thus throw.

Focusing my white flat C8 took me more than an hour, but i eventually got it right.
Reaching over 200kCd on a standard Biscotti driver :smiley:

This was taken before final focusing

Those are some excellent numbers, i hope that i will be able to hit that 200k number.

This C8 has slightly modified head and bezel, the reflector can sit and create enough pressure on the mcpcb without even needing of any type of gasket, before the mods the reflector outer lip was resting on the flashlight head and the reflector was not able to go all the way down, now without that problem i can play with the height of the reflector as much as i want, not looking forward to all that tho :confounded:

Yup, not sure what the lens was originally used for. Guessing a big rear projection TV? With a Olsen Flat black at 600 LM it did 2.6 MIll. LUX measured at 9 meters. And heres the kicker,2.6 mill with out the magical collar.


Meanwhile my collar will continue collecting dust until a new flashlight comes out