Once the flashlight is on tripod, if I note a change in readings, it’s either thermal regulation or I have touched the light to twist the lens off, etc… Meaning, if you see a lot of fluctuation, it’s because there IS a fluctuation and a good sign of how sensitive the Opple is. If you leave it alone on tripod, some examples of data:
Convoy S21D with Nichia 219b 4500k with Convoy Green AR lens - on tripod and not hand hold:
x3570 y3367 Duv –0.0124
x3570 y3366 Duv –0.0124
x3570 y3365 Duv –0.0125
x3572 y3369 Duv –0.0124
The result I posted in the thread below was confirmed by doing two separate runs, with little change in result as far as differences between lenses. Convoy S21D w/ legendary Nichia 219b :) - Review & comparison w/ Nichia 519a, E21a & other LEDs & lights (D4V2, Convoy S21F). - #296 by cannga . Really at 40 bucks I am not complaining much - a must buy for hobbyists on a budget 
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