LH351D 90CRI Spectrum Tests

Thank you,stock seem not so good.
Do you like tint when sliced?

I prefer the one from contactcr that is always below the BBL, but it looks okay.

Does dedome lh351d decrease even more the CCT and also blue peak than slicing?
Would be interest on stock 2700k

Results here :

Great
Have you tried measure spectrum at very low current like 1~3mA?
My sample at these current look much more greenish and bluish compared to 0.1A you measured,I guess Duv and blue light increase much more.
Does that will happen less with lower power Leds like E21A or the ones used for strip lights?

The current stock of SPHWHTL3DA0GF4RTS6 (dog farts) at Arrow is the worst batch of LH351D I’ve ever come across. Duv ~0.0065 at both low and high current, and CRI doesn’t even reach the rated 90. At 3A they’re something like CRI 87.5 with an R9 of 40. Even slicing them down to the phosphor still gives a significant positive Duv and sub-90 CRI. Utterly atrocious :person_facepalming:

With the new Nichia 519A R9080 having similar performance, perhaps LH351D will fall by the wayside like 219C did.

Hmm. Didn’t think of that. Maybe 519 can replace the samsung, but we’ll have to wait for tests. The newest Nichias don’t overdrive much if any, so it’ll need a big die. EDIT: The 519 has a 4mm die. The 351d has a 5mm die.

2.4A is their max pulse current. This is actually the same spec as the 219F which is a 2mm die. ‘Continuous’ rating is up from 1800mA to 2200mA. If they behave proportional to spec, then about 4.9A will be max current before the phosphor burns up. Will that be enough to beat the Samsung? That’s the question. Maybe we could see 1800lm (djozz calibration) from a 5000K 70CRI variant

If better tint and/or color quality can be more easily/consistently has from the 519A that’s a huge advantage over LH351D right there. Slicing is a (fairly) easy improvement for the 351D, but that then has tradeoffs in output and efficiency…

According to Clemence it’s the same chip as in the E21A, but with a more robust package and DTP, so it should be at least better than this :

R70 here though, on the other hand the dome will increase light extraction.

Yeah. I stick to the 1700-1800lm estimate for 5000k R70 for an m700 bin

Guys what do you think about this LH351D 4000K Sliced from simon?

Very nice! Seems like it would be super competitive with the best bins of sw35 assuming the tint is being shown true-to-life with those two shots.

Maybe I’m misunderstanding, but when you say similar performance I interpreted this as 519A = LH351D, except Duv and R9? Is that correct?

Reason I’m asking is that I’m starting to dislike the greeenish tint of the LH351D and I understand it doesn’t have too high R9 either. So replacing them with the 519a R9080 is very tempting. But since I’m just getting into all the technical specs (aka noob), so I’d rather ask one time too many than to make wrong assumptions :wink:

yes,
here is a light that I removed an LH351d
https://www.reddit.com/r/flashlight/comments/pqy1ao/sunwayman_v11r_w_2700k_lh351d/

and installed a 519a:
https://www.reddit.com/r/flashlight/comments/sm1qkc/v11r_w_4500k_519a/

That Olight i3e beam looks excellent, both in color, and beam quality! Really like the defined spot, and the spot size. Is that a customized light, or is that how it is from the factory?

yes, that is a stock Olight i3e

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I see. Single AAA battery, 2.3" long and only 90 lumens, I thought it was larger and brighter than that. Didn’t realize it was such a small light. That spot is how I like them to be though. Might have to try one. Wonder if it will run on the energizer Ultimate lithium AAA batteries? The alkaline and those ultimate lithiums are both 1.5v.

Fenix told me not to run my HL23 headlamp on the lithium battery. I don’t know why cause the AA alkaline and AA ultimate lithium are both 1.5v also. It does get a bit warmer with the lithium but I use them quite a bit and haven’t burned it out yet.

Earlier i3E were cw. Since a few years Olight spends them a nw emitter, but really glorious is the cri80 4000K variant. Really difficult to reflow since the contacts of the TX are two tiny spots above the heat transmitting pad. I had one hit and one miss. Wouldn’t do it again and hope my i3E will outlast me. Can’t imagine a better keychain light.

The lithiums are actually more like 1.6 volts “average”. But, I have measured many of them at ~1.75V to 1.8V out of the box. Take a calibrated meter to some of them if you can. I have read reviewers say that they are essentially dead at 1.4 Volts. It doesn’t sound like much to folks like us that love to push things. Apparently it is enough that they are not recommended for many of the AA/AAA devices that I have. You may be OK (probably will be. I have used 14500 cells in some AA cell lights without problems) , but if you kill it you may not have any warranty.

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