I notice a little green in my SST-20 4000k 95CRI when next to my 5000k XP-L Hello.
On its own I don’t notice any. My mind could be blocking it, like a bad experience.
But I DID use the word excessive because I do NOT like what I shine a light on to look green. Not our brownish cream colored floor tiles, not our beige carpet, not my son or anything else I look at. Green is an absolute no go for me, period and end of that story. So this E14 that just came today will get the emitters swapped again ASAP tomorrow.
All 7 of the SST-20’s that I removed from my E07 will be in the trash probably less than 12 hours from now. (as it’s bedtime here and I have something that I have to take care of first thing in the morning)
Edit: For reference I ordered my E07 with 5000K NW SST-20’s
Don’t forget, I’m a photographer and I deal with processing colors correctly in a very big way. Thousands of pictures at a time from a full frame Canon sensor on a professional Dell monitor that’s color corrected. Proper color is very important to me, it’s a way of life.
A photo of my daughter, printed on Kodak Metallic Paper at 24x36. These pics taken moments ago with my i8 locked at 4352K and with 2 lights at approx the same output. Bet it doesn’t take you much of a guess as to which one I’ll be throwing the emitters away…
Luck of the draw perhaps. But yeah, they didn’t stay in my E07 very long at all. The nice tint, on the left, is the E07… with LH351D 5000K W6 emitters.
Beam profile is nice, Turbo tint is nice, but at lower output level just a fail on an FET driver. Maybe I’ll try em on Neven’s regulated driver and see how that goes, probably the same though…
I didn’t compare heat or amps or runtime, but when I compared tint of SST-20 4000K 95CRI to an XP-L HI 5A/5D, I found the XP-L HI made a much nicer-looking beam despite the lower CRI. SST-20 looked fine at high levels, but I don’t use high levels very much.
With an amc7135 chip like the D4 uses, the bottom half of the ramp stays in regulation longer with lower-Vf emitters. Basically, it stays in regulation as long as the battery voltage is higher than the emitter voltage. Then on a low battery, output falls much like it would with a direct-drive circuit. It’s a lot like a buck driver, except it burns off extra voltage instead of converting that to current.
Heat can definitely be a problem when burning off extra voltage like this, but the 7135 chips have their own thermal regulation built in. It typically works well as long as the voltage is within spec. It doesn’t work at 5V and above though, and the chips tend to die when used that way.
I stand corrected, I understand what Blue was saying now. But to poke at this a bit further, is the Vf at 0.35A really above 3V, and in the D4 now we are talking less than 0.1A per diode. I’m still thinking you are not staying in regulation on a rechargeable li-ion battery in a D4 before the voltage is so low it no longer safe to be operating. Guess it is time to investigate the Vf for an XPL-HI led.