Simple answer: compared to the XP-L2, the Luxeon V has better output, lower voltage, better tint and no ugly yellow corona around the hotspot.
Less simple: the 4040 footprint does not really match the 3535 XP-footprint, but with a precise reflow it will work (or else get the led on a dedicated ledboard from led4power)
112lm/w 5A
But in direct drive with same config that powered xp-l2 with 5Amps you will get something like 7.5Amps with 86lm/w.
For linear drivers like LD-*4 you can just compare lm/Amp. 1653lm XP-L2 vs 1820lm Luxeon V, both @5A.
At 7A the Luxeon V puts out 2200 lumen, the Samsung 90 CRI led probably just 1400 lumen. But that is not the whole story, the Luxeon V runs at a lower voltage so the efficiency difference is even larger and in direct drive the Luxeon V will draw more current, with again more output.
That said, for a led with such good tint and CRI, this Samsung has very good performance.
For the light I’m deciding between these to use in (Sofirn SP32A / un-modded) it’s not DD and is pulling around 4.7A max at the tail, at that current what would you estimate the outputs / difference and which one would you recommend for it?
im not sure why Djozz is rating the 351D with such low output. If you look at Texas_Ace tests it pulls way higher. If you subtract like 22-25% from his numbers to account for 4000K and 90CRI you will probably be close to your estimated output.
I would guess ~1200-1250lm Samsung and ~1650lm Luxeon V? Both will look way better than the XPL2 with SMO reflector. Not much tint shift in corona. They wont be “rosy” like a Nichia 90CRI but shouldn’t be green either (this is personal preference, I guess some people like that pink color)
You are right contactcr, I substracted too much to account for high CRI, a few years ago it used to be close to 40, but I looked up the specific bins for these Samsung leds and from the 5000K 70 CRI (W2 bin) to 4000K 90 CRI (S2 bin) you loose just 18. So starting with TA’s numbers, at 4.7A you still have 1435 lm leftover, in a flashlight OTF that should be just under 1200 lumen, compared to well over 1400 lumen for the Luxeon V.
So the Samsung will be 200-400lm less output but CRI90 vs CRI70.
Hmmm tough decision, I only have one CRI90 light but it’s 5700K (Nichia 219) even though it a nice pure white it’s still a bit cooler than I’d prefer.
I’d maybe try the Samsung but I suppose I’d need to buy 10pcs ($22.05) and I don’t do the reflow so I’d have to learn that too. Luxeon V already on the L4P 16mm board, $9.36 for 1pcs. on the board (or $14.42 for 2pcs.)
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It sounds like both these LEDs are better than any 4000K Cree LEDs, I suppose i should just get both and compare them and learn to reflow, then I can upgrade many lights to Hi CRI.
If I read everything correct these are the footprints?:
Luxeon V……………….4040 (XML is 5050)
Samsung LH315………3535 (same as XPL)
Reflowing is seriously easy. If you have 63/37 leaded solder you cant get it wrong. I use an old pan i dont cook on and its super easy to tell when the solder flows.
XPL-HI 4k is nice for a cree offering. Not high CRI but good beam and tint. I still like the V better but both have their uses. Especially since the V has a unique footprint
The thermal interface is very good just like Lumileds claims. Here’s a thermal video which shows that the temperature difference between the emitter and MCPCB is very small. You can barely see any difference in color.
Current increases from 0 to 5 amps in 200mA increments every 5 seconds.
Difference between emitter and MCPCB
Also Fv up to 5A created during the automated test.
Not being a CRI connaisseur (well, I’m not connaisseur of any thing really :D) I do have to say that I have only 2 lights with this LED installed. I must say that all the nights I use them at home and I never thought the CRI was only 70
The beam, tint and the colour rendition of this led is super, even not being 90+ CRI!
Soon I will get more from led4power and I will not regret that!