Luminus SST-20-W 4000 K CRI95 color and output test

What is their reason for only selling the FD2 and not FA3? Would love some FA3 for the more rosy tint. If not, FD2 is still better than the current FB4 by far. Vinh might be interested in buying a bunch since he uses a bunch of the FB4 tints in his lights. Richard at MTN might be interested to stock some too if you can’t get the quantities you need.

At the moment I can get up to 2k I think.

The FA3 they are planning on using in an upcoming light and don’t want to let any go before that sadly.

Interesting idea, I could try talking to Vinh and MTN to see if they are interested in some of them.

Btw, output-wise the FA3 did just as well as the FB4 in the OP, 307 lm at 1A. The FD2 did 319 lumens. At 5 amps FA3 did 934 lm, FD2 980 lm (not using a copper hs like in the OP and graphite pad instead of thermal paste).

Thanks for the info Maukka. Surprised it is the same high flux bin considering the FA3 and FD2 is a better tint than the FB4.

BlueSwordM recorded interest in 412 x 4000K SST-20 so far in a group buy thread he was running. He already made a group buy of 3500K, but 4000K has been on hold for a couple of months due to not being able to confirm availability of anything better than FB4.

Perhaps FD2 is good enough to start trying to get a 4000K group buy in motion again?

Interesting, while the FD2 is the best tint out yet I would guess that FA3 or better would be needed to gain that amount of interest. That is about what I figured the interest level would be if I could get the FA3.

I am guessing less then half the interest for FD2.

I know I would want some FD2’s to play with I would not stock up on them to use in a lot of lights, I would wait for something better to come along.

It is possible we could get enough interest to make an FD2 buy worth it. I would need to sell at least half of them right away to cover most of my costs minus the LED’s I plan to keep for myself.

Who knows though. Some better LED could come along with less tint shift by the time you get this ideal tint

Yeah, part of why I am not rushing into the FD2. The FA3 was enough of a step up to be worth jumping into but the FD2 is a smaller step.

I received the batch of FA3 and FD2 SST-20 leds today, that Texas_Ace had sent to me. Thanks TA again for these.

This evening I did the test I was most curious of: modding 3 of the FA3 leds into my freshly received FW3A.

(I did all the tint checks with the FW3A’s AR-coated lens in place, I hope and think that using a plain glass lens will make results only slightly different, not much)

And as expected from the effect of the optic, even the FA3’s were not enough to get the tint in the hotspot below the BBL at any current. You have to start with very obvious rosy leds to get that done.

Also on inspection by eye, the beam has no rosiness to it.

Instead I got a very nice neutral tint in the hotspot (close to 3950K at all levels) that has not even a hint of green. Just as neutral white as 4000K can be :+1:
The beam next to my Sofirn C01S, that has a 4000K 95CRI SST-20 of unspecified tint (so likely FB4), makes the C01S look more green, so these leds have indeed visibly a different tint closer to the BBL.

The CRI is between 96.5 (turbo) and 97.6 (close to highest ramp level) on all currents, with R9 between 86 (turbo) and 98 (close to highest default ramp level).

Also at the lowest levels the hotspot has no visible green. The duv went from 0.0015 (very low level) to 0.0022 (highest default ramp level) to 0.0005 (turbo).

For comparison, the Sofirn C01S has a duv of 0.037 (high) and 0.034 (low). (The C01S also has a TIR optic, but it may be optically a bit different from the Carclo 10570).

I feel quite spoiled to have such nice leds in my FW3A.

Later (I hope tuesday) I will check a FA3 led and a FD2 led in a S2+ reflector at a few relevant currents.

This would be great! Thank you for sharing your findings too!

Guys, if you can offer me somewhere to put a payment, I could order those LEDs.

Would be nice for my 3rd gen BeCu springs+ LED GB.

I can order some FD2, the FA3 are not available sadly.

If you want to get some FD2 let me know. It is a 500pc minimum order last I checked.

500pcs is easy now that we have quite a bit of interest.

Just need to revive it in my thread.

That sounds really nice. I’m definitely curious about your results with different optics, and in particular, with an uncoated lens.

In the D18 that I have, the SST-20 4000K are very close to the BBL line. For turbo (10528 Lm) I got 3944K and Duv 0.0010. At a lower power, 850 Lm, the color is 3970K and the Duv is only slightly higher because 0.0012. I’m very happy.

Good info. Seems like Emisar might have gotten their hands on some FD2 tints too.

I got similar results, very well could be FD2.

Something lower above moon and below top of ramp:

CCT = 3893K (Duv 0.0033)
Color Rendering Index (Ra) = 96.6 [ R9 = 94.8 ]

Top of ramp:

CCT = 3895K (Duv 0.0012)
Color Rendering Index (Ra) = 93.7 [ R9 = 79.2 ]

Turbo:

CCT = 3879K (Duv 0.0010)
Color Rendering Index (Ra) = 93.6 [ R9 = 79.1 ]

Since I replaced all my D18 LEDs with 219B I did a little test with a frosted narrow Carclo 20MM TIR using the old SST-20 4000K from Emisar D18:

Result is XYZ: 328.591970 327.669203 191.744281, Yxy: 327.669203 0.387488 0.386400
Ambient = 327.7 Lux, CCT = 3887K (Duv 0.0025)
Color Rendering Index (Ra) = 97.3 [ R9 = 96.7 ]

Result is XYZ: 882.429254 877.078547 519.529607, Yxy: 877.078547 0.387194 0.384846
Ambient = 877.1 Lux, CCT = 3882K (Duv 0.0018)
Color Rendering Index (Ra) = 97.3 [ R9 = 94.7 ]

Result is XYZ: 1139.849852 1132.186200 684.048856, Yxy: 1132.186200 0.385594 0.383002
Ambient = 1132.2 Lux, CCT = 3910K (Duv 0.0014)
Color Rendering Index (Ra) = 96.7 [ R9 = 91.7 ]

Result is XYZ: 1987.408736 1947.756714 1216.169431, Yxy: 1947.756714 0.385805 0.378107
Ambient = 1947.8 Lux, CCT = 3867K (Duv –0.0009)
Color Rendering Index (Ra) = 96.5 [ R9 = 89.9 ]

How long do you think one of these will last me @ 5 amps in my M21A (regulated to 55C, but the led itself would likely be much much hotter)? Trying to figure out if I should buy a few spares or learn to solder, etc…

It should last a good long time. With a DTP mcpcb you are unlikely to have the LED die in any flashlight to be honest. I think I have had 1 LED die in all the lights I have used that was not caused by something I did (and even this one was questionable since it was one of the first lights I built).

The LED is rated for something like 125-150c BTW, so 55c is nothing for it.