Sliced XHP50.2

Flash max: the LED is an 80+ CRI 3000k stock. I haven’t noticed a considerable tint shift and i stupidly didn’t take a pre photo for comparison.

Light bringer: I’m not sure what you mean by distributed phosphor. I’m pretty new to flashlights and modding but I like to dive into things headfirst at the deep end with a lead helmet.

Thanks Thom, maybe these emitters does not suffer of a noticeable tint shift.

SORRY EVERYONE I F**KED UP!!!
my readings are NOT kcd they are k lux.
My appologies

A well-driven sliced XHP50.2 (you need two 18650’s in series for this) in a C8 can (educated guess) maybe do 100kcd, probably less.

I’m using 2 VTC5’s in series, in direct drive I’m getting ~10A at tail cap.
How do I convert from lux to cd? I just used rapidtables converter and it’s saying that 196k lux is 259kcd.

This is all new to me so I’m probably in need of some educating.

To convert lux to kcd you need to know the exact distance. For example I use 5 meters (the longer the better), so to compute kcd:

meter reading * distance * distance (distance squared in meters)

If you measure in true lux (typically I use the 10X setting), then for 5 meters multiple by 25 to get cd. kcd is 1,000 cd. We usually quote kcd - no need to add decimal digits - our meters ain't that accurate

Regular “old” LEDs would have a phosphor coating right on the chip itself, which is why white LEDs look yellow.

“Remote phosphor” would be a plain blue LED, but the phosphor is off the LED, like screw-base lightbulbs with blue LEDs but yellow-looking plastic “shells” around it that convert blue into multi-spectrum “white” light. On an LED it might be a hollow silicone dome but with the phosphor coating on the inside of the dome. Dunno any that do that, though.

“Distributed phosphor” would be having phosphor powder/flakes/whatever being mixed into the silicone itself and then formed into a dome or coating.

If you look at a G2, you can actually see the chip through the clear dome. The G3 looks like it’s got an orange dome itself on top of the LED.

I don’t have any G3s (only ordered some G2s for the first time), so I’m only going by the pix I can find online, not having an actual chip to eyeball.

G2 vs G3 (pic from TLF):

Eg, remote phosphor bulb:

Ahhh, interesting stuff! I can currently only speak for the 50.2 but the dimes is definitely clear. The bits I sliced off are definitely 100% clear. As said I think the ‘yellow dome’ effect is caused by the fact that the entire visible surface of the LED is coated. I have a few G3’s on the way for experimenting. I will let you know my finding.
I will also go away and take some more readings at greater distances to give more accuracy and also take some readings for my M2 and TN4A as comparison.

I’ve been slicing and dicing a number of these new cree LEDs and so far am reasonably liking the results, unfortunately not the same throw as certain other older LEDs but for the lumens pretty respectable. For a comparison, all in a Jaxman Z1, XP-L2 ~190kcd, XP-G3 ~200kcd, XHP-50.2 ~190kcd. Although compared to the 400+kcd the SoH does in the same host they are not that impressive.

Could be the manufacturing process, then.

Old way, apply phosphor, then mount the completed chip on the substrate.

New way, mount the chip inverted, spraypaint the phosphor after.

Just guessing…

That’s the way it looks to me. Phosphor after assembly would probably result in a significant reduction in rejects.

Nice work. Please let us know your results with the xpg-3’s and if you can scrape around the die on those as well.

XP-G3 close shave to about .005’’ silicone remaining.

Yes you can scrape the edges…

And both XP-G3 L2 50.2 and soon to be 70.2 are crap for throw IMHO! And they can’t be de-domed with out pulling the phosphorus off, I have tried!!

But you can de-dome the old XHP70-50 and 35’s!

I can confirm that all of the new Cree emitters have a clear some, and the yellow appearance is just because the phosphor covers the whole chip. I have XP-G3, XP-L2, and XHP50.2, with XHP70.2 on the way. I thought they were distributed phosphor as well until I had them in hand. Looking at any of them from the side the dome is crystal clear.

I like the new emitters, better efficiency. Never cared much about throw though, and I like warm tints so the color change in the beam is less pronounced.

Hey guys so here’s some proper, measured and error corrected tests of the following.
Convoy C8, smooth reflector, sliced and scraped xhp50.2 80+CRI 3000k, direct drive, VTC5’s @ 3.98v(I stupidly forgot to charge them)
Convoy M2, orange peel reflector, sliced XM-L2 ?? 4C, direct drive, fresh VTC5
A bone stock TN4A XPL Hi NW. Fresh eneloops.

Some testing info:
Tests were done at 3 meters.
My lux meter states that under 100k lux it’s accurate +/-4%.
I assumed that it over read by 4% so corrected as follows.
(Reading / 104) X 100

The results;
C8: 82890cd
M1: 17982cd
TN4A: 54684cd

I feel confident in this correction as the TN4A spec states 52340cd and I measured and calculated 54684cd
Without correction the TN4A result was 56880cd.

My XPG3’s have been shipped. When they arrive I will add their results into here aswell and make sure I get some good comparison shots.

Anyway I hope this comparison proves useful to someone.

Nice result with the C8. Thanks for the measurement.

Just some personal notes I made testing these last year. My measurements are simple relative measurements.

Surface brightness comparison
XPG-2 S3 8.6
XPG-3 S5 7.1

Corrected surface brightness (like for like binning). Shows effect of differing phosphor application.
XPG-2 9.8
XPG-3 7.1 = 38% decrease in surface brightness with dome on.

All dedomed
XPG-3 modded with the one chip subdivided into three distinct sections.
Stock shaved dome 3.3 - 57% dec over XPG2
Shaved plus thin silicone coating 4 - 48% dec over XPG2
Transplanted XML phosphor 4.7 –39% dec over XPG2
XPG-2 S4 7.7

Same here, big intensity decrease by shaving my XP-G3 dome.

Im confused? Dedoming these LED’s reduces surface intensity? How’s that work then?

Total intensity decreases. but since the apparent size (magnifying-glass removed) is smaller, intensity per unit area is higher.

Eg, if the chip looks only 50% of the dome-on size, but loses 30% of the total lumens, you’re getting 0.7 of the light in only 0.5 the size, or 1.4× the surface intensity (40% higher). You’d have to lose fully half the total lumens for it to be a wash.

Just pulling numbers out of my… hat… so keep that in mind.