They are XP-L sized. I think they should be compared to the XP-L2 90CRI 4000K 2-Step, which is very efficient, but has a terrible tint (Duv 0.6 in the low/mid modes with reflector - SC64c). So this LED is indeed much better, similar to the Nichia 219C 4000K R9050 (which has a somewhat yellow tint though). At high currents it is probably noticeably brighter than the 219C R9050.
EDIT: I just checked the datasheet. At 3A the Vf is only 3.28V and the thermal resistance is 2.2°C/W. So it’s actually quite compareable to other XP-L sized LEDs. 765-810lm @3A & 85°C. 77-82lm/W, so definitely worse than the XP-L2 in that regard, but only because of the used Bin.
EDIT2: I just compared these measurements to those of the Nichia 219C 4000K R9050 403. The Samsung LED has a higher TM-30-15 Rf & Rg, a higher R9-value and a more balanced spectrum. The Duv ist very similar (unfortunately…).
Played with Lee Zircon minus green filters. The results are promising and visually the light is gorgeous. It really makes every color pop, even over saturate (Rg 102). I think I’ll stick with the 804.
Now I have left only 23pcs of 351D and 4 people send me PM
I’ll send these 23pcs. Then I’ll order more 351 in a week(+3 days to get it).
So please express your interest in this thread, I’ll make a list.
Small discout for orders >20pcs - 1.5$/pcs
Thanks for the measurements! I have a sheet of 804 at home, as soon as these arrive I’ll make good use of it. By the way, does anybody know where to get some good optical glue?
I’m not sure. The die seems a bit bigger compared to that of the XP-E2, but everything else (max current etc.) is the same. Unfortunately they only have the 90CRI version with ~3000K.
That LH351B looks quite good too imho. According to datasheet its flux bin can be F1 (90 - 100lm), G1 (100 - 110lm) or H1 (110 - 120lm). Which one is it? This translates into 297 - 330, 330 - 363 and 363 - 396 lumen ranges at maximum specified driving current (1.5A, 3.3x multiplier). If dedomed should be perfect for throwy small flashlights with high quality output.
By the way, do these (LH351B/D) feature bond wires? I'll try super fine grit sandpaper dedoming with them.
I swapped the led in a Sofirn SP33 for the 4000K 90+CRI Samsung LH351D, and I’m in love with this led. Texas Ace already showed with a 5000K low CRI version that this led has great output and can handle a lot of current, I can confirm what maukka found: this 4000K 90 CRI version has a very good tint (and colour rendering of course), and it behaves absolutely fine in a smooth reflector.
So I swapped the led, I bypassed some springs and fiddled with the current sense resistors, and now my SP33 puts out 950 lumen OTF at 3.8A current, which is quite an achievement with light of this quality.
I’m almost convinced to swap these leds into my Q8.