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

I lose about 30% output slicing the dome at the bond wire height, with no increase in throw but a noticeably rosier tint. Increasing the intensity requires trimming the dome around the die and carefully slicing as close as possible to the phosphor while avoiding the bond wires. The stock 3500K SST-20s I’m using get about 600m throw in a D1S/GT mini, which I was able to increase to 685m with careful trimming. It’s not pretty, but it works, and it could probably be increased further. This is the best option for a high CRI thrower right now.

30%? Ouch. I guess it will be better using a minus green filter to correct tint as there will be less risk? Do they decrease throw/intensity at all?

What is it about slicing that makes the tint rosier?

Do different depths of slicing have different effects, i.e. do deep slices, as close to the phosphor as possible, result in the rosiest tint, with the best increase in throw but at the expense of the biggest sacrifice in output and vice versa?

How about Luxeon Z ES? It’s just CRI90 but maybe it will throw significantly better?

I just shaved 12 SST-20 domes in 3 D4’s. Been reading how they got rosier, had to find out. Started with the one I cared the least about just to experiment and ended up slicing them all. I thought my 4000K version was a wee bit green and my 3000K a bit yellow. Now I have white and rosy. The beam profile is maybe a little more wonky but only if you are looking for it on a white wall. I think these are pretty sweet little LEDs for what they are.

Any comparison beam shots or tips on how to slice?

Yeah when I get off work. Beam shots suck on my phone, but I had a 3000K 4000K mixed D4 and when I shaved them it made my straight 3000K D4 look pee yellow when in reality it’s not. Then I did the 3000K D4 and it’s a much nicer rosy color than yellow now. Took any hint of green at lower levels out of my 4000KD4. No I don’t have too many D4’s.

Hodor, my phone doesn’t really show the difference in tint well, but take more word that it improves. I didn’t get too excited with the preciseness of the slicing. Just got pretty close to the phosphor opposite the bond wires and when I got to the bond wires just angled up. So a side view looked like a little ramp (half) half pipe. Didn’t seem to be too crucial to get it as close to phosphor as possible.

I can attest to the tint improving but the output does go down and since the beam narrows even more it makes the beam pattern look different. You see a starburst type pattern (at least in a carclo triple) more clearly at the edge of the hot spot.

I honestly wouldn’t recommend it unless the green makes it unusable to you or you dont mind replacing the LEDs if you dont like it.

Good input contactcr. That is all true, but for me, preferable. I just went out in the snow to test against my 219C D4. I quite like the extra throw. A little bit more like a reflector light. I don’t have a lumen tube but I’d say the loss is not nearly as perceptable as the tighter beam profile. So I’m a vote for just do it. Depends what you like hodor.

I took some measurements of my dedomed SST-20 GT mini. I’ll add data for the stock LED when I have a chance to install one in a light. It looks pretty nice on turbo, though it’s really too warm for my tastes. But, it’s a rosy high CRI laser thrower, so I suppose I can suffer through it :smiley:

Low
CCT = 3237K (Duv 0.0017)
Color Rendering Index (Ra) = 98.1 [ R9 = 93.0 ]

Turbo
CCT = 3349K (Duv –0.0023)
Color Rendering Index (Ra) = 93.5 [ R9 = 71.8 ]

Nice, what meter do you use?

That’s measured using an X-Rite i1Studio and spotread.

TA sent me some more SST-20s. Tint bins FA3 and FD2. The FA3 turned out to be pretty good at the BBL already at 1A. Maybe he can guide us on where to buy them?

:+1: it looks like progress in getting what we like. Thanks TA and maukka for the effort.

Indeed. I so wish it will be generally available in the near future….It negates the biggest issue with this otherwise-great LED.

Great, thanks for the test results maukka! Glad these are not flat out lies like the “FA1” that turned out to be FB4.

Djozz your samples should not be far behind (sent samples to both of you since it was only a few extra bucks and I knew you would both be interested).

Far as ordering them, sadly that is not possible for us normal people, it was from some wholesale distributor in china. I have spent the last few months talking to luminus and everyone else I can find to track these down. Ended up that these popped up at some distributor Mateminco knew and they snatched them up.

That said I am trying to get my hands on some of them and if that is possible I might run a group buy if there are enough to go around. There are only around 800 FA3 in the world that I could find but there are more FD2. Not sure how many I could talk my way into as they don’t even have enough for the MT18 they are planning to put them into.

I will update you once I know more about availability.

I suppose that’s supposed to be aren’t, since to me these seem to land where they should? :slight_smile:

lol, good catch.

Thanks TA and Maukka! Finally some good 4000k 90+ CRI emitters. The FA3 is further below the BBL whereas the FD2 is still mostly above the BBL so I think the FA3 should have much better tint especially when used in mid and low output. It could be just the random sample though. Hope we can get a group buy for these soon to be extinct good tint SST-20.

Huh, guys I just noticed.

The SST-20 4000k is now available on Mouser.

Will ask for the tint bin.

Might be good like the 3000-3500k, but I really doubt it.