LH351D 90CRI Spectrum Tests

for a 2700k option I think the SST-20 might have higher R9 than the 2700k LH351d… not sure… I have not compared their specs…

here is a link to the Warm SST
Luminus SST-20 J3 JA3 Warm White 2700K CRI95 LED Emitter


pic is a link to the warm LH351d source

How does the LH351D 90cri compare to a nichia 319A (80cri) in terms of efficiency and beam pattern? Thinking about swapping to a higher CRI LED in my Quark Mk III…

the higher CRI LED will be less “efficient”, inasmuch as it will produce less total lumens

CRI, and especially CRI R9 go up at least as much as lumens go down

imo, it is worth the trade.

now, depending what CCT you are interested in

there may be reasons to choose 219b over LH351d or SST-20
Im not sure yet, which I would prefer, have not tried the SST for example
I do like the Nichia more than the unsliced LH351d…

for my pink biases the LH351d needs to be sliced,
that also comes with a lumen penalty

If the die of the 319A is close to that of the 219C, the LH351D will be floodier but probably still have more output/be more efficient even binned at 90CRI. The LH351D has a die size right between the XP-L and XM-L2 IIRC.

It’s actually bigger on the LES vs the XP-L die.

I’ve actually become quite fond of the 4000k sst-20 but I believe those would be even less efficient than the LH351D. I have a few lights with that and while the r9 does lack a bit it seems overall quite nice. I’d really like to keep this as bright as possible and the 319 is doing alright for now… just love my high cri options!

I think you might have a 319a D340, if thats true, and you go to a sw45k D220… you would see a 35% lower output… sounds like you might not like that… but

let me play CRI advocate…
say your light makes 340 lumens now
and with a sw45k, lets say it “only” makes 220 lumens

the low CRI is only 54% brighter… that is not really a big visual difference
and you give up all Red rendering… to get those extra 120 lumens… is it worth it?

you know best… :wink:

lucky for you, that version of the quark is not glued… tinker on!

Sorry, that’s what I meant unless XM-L2 LES is same size as XP-L? I only assumed larger due to the pad.

HDS has adopted the LH351d 5000k as its next High CRI offering.

It produces 300 lumens in an HDS
the sw45k produces 200 lumens in an HDS

so the LH351d is 50% brighter than the sw45k
equivalent to one hop on the HDS dial.

the LH351d is a 9050 LED with tint above the BBL
the sw45k is a 9080 (more red), with tint below the BBL

The Samsung LED still has better cri and r9 than the natural light coming in my office today:

Two measurements taken in Texas, today at 2:45PM, overcast day. First is indoors with no artificial light, only ambient light from window - the next measurement is when I step outside.

like of your anDroid ColorMeter app :+1:

good time for a dogfart :person_facepalming:

can you also show the ColorMeter data screen for the LH351d 5000k please?

Here is the Sofirn sourced 2700K LH351D

Very similar to the DigiKey one I tested but with a better price.

1Amp with Frosted TIR:

Would be interesting measure after slicing for know if DUV and CCT decrease at very low current.Cheers

Here it is sliced in a Sofirn C01S AAA small TIR on the “100 lumen” setting. Not exactly apples to apples but you can see lower DUV but not much change in CCT. I cant explain why that is, maybe LED tint variation but probably just the optic doing strange things. It’s not really meant for such a large die. There is also a little ambient light in room.

I emailed Digikey the other day to ask about some color bins, I didn’t ask for a lot because I doubted they would reply, I got the reply today :

SPHWHTL3DA0GF4WPN6 (2700K) : 798 pcs F2 W7 N2
SPHWHTL3DA0GF4UPP6 (3500K) : 759 pcs F2 U7 Q2
SPHWHTL3DA0GF4TPQ6 (4000K) : 481 pcs F2 T6 Q2

Not sure how this info is valuable though because we don’t know if the bin you tested last year were the same.

The 2700k and 3500k were always the best ones so I’m not too surprised by this.

We have seen T6 be above bbl from other vendors so it seems like these squares if meaningful generally tend to be at the very top of the square/bin

Side note; CONGRATS on getting one of these mega distributors to answer this. Didn’t think it was possible.


If I can muster up the energy I’ll test my Convoy sourced 5700K 351D tonight or tomorrow. Don’t think we have seen one of these in the “wild” yet. I think these were from some stadium lighting so I suspect mega green but we’ll see…

Thanks for all your testing contactcr. :+1:
My favorite is the 3500k UPP6 from digikey sliced.

Yeah, plus with 4000K and up the middle of the quadrangles is raised above the BBL, probably to merge with daylight tint (~ 0.0030 duv), on the other hand, integrated duv should be slightly lower than measured at the spot (but maybe not that much with the frosted TIR you used).

I was doubtful they would bother to check for me yes, I got no reply for ~10 days so I though they ignored me.

:question:

Simon wrote the bins he got and it’s Q2 (5700K) and R2 (5000K) so the lower duv bins. I have some 5000K coming (not interested in 5700K) so I’ll see how they test. By the way I measured my FC11 and it’s actually worse than yours :
5170K (Duv 0.0086)
(Ra) = 87.6 [ R9 = 30.8 ]

It’s quite strange, not 90 Ra and low R9.

Convoy Sourced LH351D 5700K 90CRI (bin: V2Q2S1)

Frosted TIR, same as before. The results are about what I expected. I purchased these mostly for two reasons: slicing and tint mixing. For both purposes they should be acceptable.

1 Amp

2 Amp

Thanks for getting those tests done! No surprises there but at least some Lee filters could help with the slight green tint.

I’ve got some incoming to see what slicing will do. Hopefully it’ll produce similar results to sliced 5000k dogfarts.