outstanding info!
thank you for taking the time
the largest change you are reporting is 40% at the 100 lumen level, without touching the light, and the change occurs as the light warms up. That is in the visible range, but most people would not notice.
The largest drift you see is 15% from cold to warm, with a 200 lumen setting… awesome! That is well below visually noticeable change…
at the 500 lumen level, once the light is warmed up, rotating it 180 degrees only produces a 12 lumen change, which is only about 2%.
My tests also show that at the lower levels, the change in lumens from turning the light 180 degrees is larger, than at higher lumen levels. That is why I chose to use a 100 lumen target for my tests. I do see larger drift at lower levels, but I dont actually notice unless I use a light meter, when testing my RRT-01 with an N219b 4500k
I have not researched the effect of warmup time, so thanks for making me aware of that variable as well.
moving forward it might be useful to begin to tabulate the vF of the leds being modded in, for now Im just happy your LH351 4000k 90CRI is working so well.
I have a hunch that your LH351 has a lower vF than my N219b, and that the N219c has an even lower vF, but I have not confirmed these details…
my present take away from the tests, is that LEDs with lower vF drift more, but, I dont have data to confirm that… Im just happy my 219b does not have the problem I saw when I tried a 219c in a V11r
the lower vF issue is my main concern about the E21a, I hope Clemence does not find it to be a problem, otherwise, I would want to stick to 219b mods, because of the higher vF. I would not be suprised if all these vF issues could be sorted by additional changes to the resistors in the magnetic ring circuit, but I dont expect to burden Clemence with redesigning the driver… time will tell what he will discover, when he has the time to investigate an E21a mod to the new RRT-01
congrats on the High CRI upgrade
enjoy your light!