I am not aware of any way to get the optics by themselves. I don’t know what they are, or if they come in more than one style.
I haven’t seen a SST-20 which wasn’t greenish on low modes. It’s just how that particular product line works.
As maukka showed, the tint green-shifts on low, and red-shifts on high:
Tint-mixing helps with this, but I think I had too many 4000K + 5000K emitters to pull the low-mode tint below the BBL.
No, this is significantly more throwy than M43 or ROT66. M43 has a big wide hotspot and basically no spill. ROT66 has a slightly smaller hotspot, and also has spill around it. D18 has a significantly smaller/tighter hotspot and even more spill. SP36 is even more throwy, with its larger reflectors, but it only comes in cool white so far and its spill area is kind of a mess.
I’ll get the cd/lm measurements in a bit; kinda waiting for something in the mail. In any case though, the D18 is more throwy than the other many-emitter soda can lights, and it also puts out a lot more lumens.