What I did do:
(perhaps this is not the right thread for this, but I already started it here, sorry about that)
I sliced the 4 LH351D 4000K 90CRI leds in my SP36 sample, and took some measurement before and after.
The sliced leds in reflected light show that I sliced very close to the phosfor, on many areaās all silicone is gone on top of the phosfor layer (and perhaps a tiny bit of phosfor too but that does not show up when looked at the lighted leds)
I should also have done tint tests before the mod, but I forgot them :person_facepalming: . So the tint results before slicing will be represented by the hotspot of a Q8 that I have that has the same leds, that should be similar.
Hotspot of Q8 with intact leds, low 7135 under 350mA current (so under 90mA per led):
Hotspot of Q8 with intact leds, highest FET current (over 4A per led):
Hotspot of SP36 with sliced leds, low 7135 under 350mA current:
Hotspot of SP36 with sliced leds, highest FET setting:
Hereās the beam of the Q8 with intact leds compared to the SP36 with sliced leds next to each other on a white wall. Phone camera white balance set to sunlight, the tints are not completely accurate to reality, but you get an idea. The tint difference is larger in reality than in this picture.
In my own experience the tint went from ok but not really nice (unsliced) to super-nice, rosy and not yellow, nice both at low and high current. The tint improvement is larger than the tint/CRI data suggest.
I did notice some slight rings in the beam after slicing the leds but that is a SP36 thing, has nothing to do with the leds. It may even be just present in the prototype SP36 that I have.
Now for the output loss, I did measure that before and after. As I noticed before in other mods with it, after slicing the 4000K 90CRI LH351D, I lost a lot of output, more than with an oldschool Cree dedome.
Measurements with fully charged 30Qās.
Before slicing: 3seconds 4250lm, 30 seconds 3940lm
After slicing : 3seconds 3490lm, 30 seconds 3235lm
So the loss is 18% compared to before slicing. One must suffer for getting the perfect tint
The final cost of changing the SP36 from 70CRI cool white with tint shift in the beam (the stock XP-L2 leds, about as bright as this host can go) to 93CRI 3500K with no tint shift in the beam (the sliced LH351D 4000K 90CRI leds) is 34% light loss. For me that is an ok price payed.