[Review] SST-20 in FW3A is divine!

Tint is quite perceivable, and multiple studies have clearly demonstrated most people prefer a tint no available bin of SST-20 can achieve even at unsustainably high currents. I don’t want a light that’s 0.0016 at a level I use regularly when I could just use a 219B and get a much more pleasing neutral or rosy tint that becomes even rosier at higher outputs. There is still strong demand for 219B years after it was discontinued precisely because no other LED can replicate what it does, except perhaps E21A, which is impractical to use in most lights due to the lack of mounting options.

I may not have explained completely either. I’m not aiming for a meter-verifiable value of 0.000 duv. I’m aiming for something which I think looks good in person… like ~4500K with negative duv.

Adding a minus-green filter is a pretty common modification when using SST-20 emitters, LH351D, and sometimes others. The 89% transmittance value given earlier is a bit generous though… the range I generally see is 70% to 86% transmission, and I’m expecting to need roughly an 80% model to get most of my greenish lights down to a nice-looking tint.

As is, when I use this SST-20 FW3A outdoors, the grass looks nice and green… but so does the sidewalk. And when I point it at purple-colored objects, they turn blue. When aimed at objects with several shades of green, I find it difficult to tell the shades apart. It’s all lemongrass. So I’m hoping a filter can fix that.

I recently ended up with a D4 SST-20, which demonstrates the low-mode tint issue pretty vividly. If I put it in stepped ramp mode, steps 1 to 4 are green while steps 5 - 7 are white. If I make it go back and forth between steps 4 and 5, it looks like two different lights… green, white, green, white, green, white. Because of this, I’m tempted to convert it from a FET+1 light to FET-only, to make the tint usable below 150 lm.

… except for hitting the tint sweet spot which studies have found agreeable to the most people.

It can be tint-corrected with a minus green filter, but after filter losses it ends up making fewer lumens per amp than the aging 219B.

It’s definitely old, but there are good reasons why people still prefer 219B over 219C, why people prefer XP-G2 over XP-G3, and why SST-20 isn’t universally loved. In the quest for ever-increasing efficiency, several different LED manufacturers over the past few years sacrificed optical quality for higher total output.

The changes, like in Cree’s current-gen emitters, make a lot of sense for use in lighting fixtures where the LED is meant to run near full power all the time behind a diffuser. In that sort of device, the Cree rainbow doesn’t matter and neither does current-related tint shift. It only needs to look good when integrated and running at the recommended power level.

That sucks a bit for flashlight purposes, but flashlights aren’t a big enough market for LED companies to really care. So we’ve been using a lot of old stuff lately instead of always adopting new tech.

In any case, the point I’ve been getting at this whole time is: There is no One True LED. Different people prefer different lighting, and that’s okay.

Not everything, but an ANSI white chart should answer a few questions…

CCT goes lower left to upper right along the dotted line. Tint goes up and down along the more vertical lines. “Duv” is the distance from the dotted line. The shades most people prefer are below the dotted line between 4000K and 5000K.

The SST-20 4000K emitter this thread is about would fall into the 5A3 square, according to its official specs and the measurements it gets on turbo. However, at lower levels it shifts up and to the right, to about 5C4.

The “FA1” bin mentioned a couple comments ago is “5A1” on this chart. It might be a decent tint for SST-20, since at low levels it should only shift as far as 5D2. However, as far as I’m aware, no one on this site has ever acquired any in the FA1 bin. They don’t seem to exist. Most SST-20 around here are the 5B4 bin, which is roughly 5C3 at low levels.

My 2c:

Some time ago I owned two D4S, XP-L HI 3D 4000K and SST-20 4000K because I wanted to check which I prefer and leave just one for myself.
The throw was nearly the same, I had problems to determine which throws further.
But with both lit up at the same time, the SST-20 tint was obviously biassed with green. And I’d guess SST-20 boils up 20% sooner.
For these two reasons I sacrified high CRI for better tint and less heat. XP-L version is still with me.

(After all I still consider SST-20 to be a great LED. But similary to 219B - it just should not be pushed hard. A perfect diodes for keychain or other small lights)

I agree…. Love my 219B’s. And there are many out there who would agree.

Thank you! This was very informative!

Do you have a link to the filter products you are referring to? I would like to have a look.

I’m surprised nobody seems to complain about rosy tints. I have an equal dislike for rosy tints and green tints.

It seems green-tint phobia is a thing?

Yes.

I don’t actually like rosy tints, which is why I dislike the 219B, which I’ve actually seen in real life.

I prefer the FD2 SST-20’s tint.

Of course, we can’t deny that the current high power LEDs that have the best tint are the E21As, and in the mid-power range, the Optsolis.

My 5000K E21’s have major changes at powers above 700ma. Granted the worst in this CIE are just bare emitter.

+1. It may well be that, statistically, more people prefer rosy Duv to green Duv, and maybe even to perfect BBL. But there must be a significant, if silent, minority, that, for general usage, prefers no Duv. Just as, I guess, I find myself in what must be a significant minority of people who prioritze CRI over tint. My eyes can compensate for tint variations, but there is no way to compensate for low CRI.

Well i like rosy tint, especially at night during work. So much easier on your eyes than other tints/colors

For daytime ops SST20 looks better

I would be surprised, but this matches what the researchers found. There was always someone who complained, no matter which tint was used… so no single choice will please everyone. However, the tints which had the fewest complaints were rosy to a degree of approximately –10 to –15 mduv.

It may also relate to the old idiom about rose-colored glasses. The phrase didn’t come from nowhere. Humans, in general, seem to find a touch of pink to be a bit more pleasant. Meanwhile, the counter-idiom of jade-colored glasses (or being jaded) refers to a more unpleasant outlook.

The ones I see discussed most often are the Lee minus-green filters. For example:

$2 for a swatch book, if you’d like to try a few.

Neutral > Rosy > Green is my order of preference.

Compared to super green LEDs like the FB4 SST rosy ones look much better to my eye. However if I have a neutral tint (FD2 SST 20 and my good tint lottery 219cs in my D4) I find I much prefer it to a particularly positive or negative DUV.

To me the SW45K looks great next to super green LEDs, but when I compare it to any emitter that’s remotely neutral it looks pretty bad (even if it ends up making me perceive all others as “green”). It’s offensively rosy in the same way some are offensively green. That’s just my experience anyway ¯\/¯ The FD2 is as close to perfect as I’ve seen so far.

Has anyone tried minus green filter on glasses?

haha, that seems to be what people want :slight_smile:

these will substract maybe a bit more duv than required

Ah ha! It’s actually a Locus that merges the BBL and the Daylight Locus. Very cool. It does so by using the 5000k-4000k region to transition.

But… WHY? If the Daylight Locus is more green than the BBL, what is the supposed advantage of “merging” them this way? To say it another way: What light source is anyone measuring that they’d want to skew the “results” in this way?