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

It does, I build my scene flashlights with wide optics and very limited mode selections. The camera is very easy to adjust to the inbound light levels. The R9080 really makes colors pop and that is why I use them. I suspect with the FD2 I will end up running singles at 3.5 to 4.5 amps and triples will only be used in FET modes. The R9080 lights will be used when lower output levels are needed.

How about a MCPCB that splits the LEDs into like 3 banks and then only ramps up 1 bank at low levels, until you pass a threshold and it turns on the 2nd and 3rd bank of LEDs :slight_smile:

That would be really neat. I would want about 2 amps per channel across a triple for the R9080’s and maybe what 3 amps per SST-20? Getting all those wires into the head of a light might be a challenge and then there is the driver… 3 FETs with some PWM control each.

While technically possible it would add a lot of complication for minimal benefits in practical terms.

An FET channel can be PWM’ed down to around ~150-300 lumens in most cases (technically much lower then this but you loose resolution that low and it can be inconsistent light to light). So above that the tint will be good. Creating multiple channels for under that lumen level would be very communicated and not help all that much since the tint would still be bad.

Good idea though.

maukka, does your equipment allow calculating radiant flux?

At least with a spectrum you have all the information to read radiant flux, it is a matter of what is in the software.

What’s the highest amperage these emitters can take? Thinking of a triple sst20 in direct drive.

So an FW3A in other words? FW3A is direct drive on turbo. They can handle it.

They die at 7 amps per emitter.

The data for that, and answers to several other related questions, are provided in quite a bit of detail in the first post of this thread.

Has someone started a group buy for these emitters? I would be interested in trying some out.

Harvest them from an FW3A and then put something else in that :slight_smile:

I would but now that i have looked up what the FW3A is, that is too nice to tear apart. Eventually it may become part of my daily rotation.

Then just get the FW3A to use in stock form and experience the SST20 that way. :slight_smile:

User BlueSwordM ran a group buy, but has reported it is now all done: and sell bare SST20’s, although the FB4 tint bin they have appears green tinted to some users. Others don’t notice.

I fixed my FW3A-SST20 so it doesn’t look green any more. I added a Lee 248 “half minus green” filter between the optic and the lens.

It’s a really nice shade now, but the lumens are even lower than the already-unimpressive numbers it started with. I measured three lights just now at the 1x7135 (350mA) level in my lumen tube…

  • XP-L HI 3D: 143 lm
  • 219B 4500K: 91 lm
  • SST-20 4000K w/ minus-green filter: 70 lm

The efficiency is pretty bad. 110 lm/W for XP-L HI, 70 lm/W for 219B, and just 54 lm/W for a rosy SST-20.

I also tried a Lee “quarter minus green” which would increase the lumens a bit, but I didn’t think the effect was strong enough… so I went with half minus green instead.

As a nice bonus, the pink filter is clearly visible through the lens, and it looks really nice inside the purple FW3A host.

So I finally have a 4000K light I like. :slight_smile:

TK, where did you get the Lee filtets? I don’t need a whole collecting.

I got some big sheets of the 3 most popular types IIRC awhile back, I will never use all of it.

Send me a message if you want some, I can sell a piece of each of them if you want.

I think I got them off amazon?

where to buy
Lee Filter Swatch Book


Based on maukka’s numbers I projected the following data for a Convoy Biscotti driver and an SST-20. Does this look right? The 1/10th resolution lumens are directly from his data, the mutliple decimal resolution lumens are from a 6th degree polynomial I created in Excel based on his numbers. Clearly the fit isn’t perfect as your approach 0mA but I bet it isn’t too far off (estimate 0.5lm at 2.8mA).

I did a test of blending two different LEDs and the CRI came out right between the two sources, essentially averaged:


data from Opple Light Master