LUX averages for the moon:
0.002 lux Moonless clear night sky
0.01 lux Quarter moon
0.27 lux Full moon on a clear night
1 lux Full moon overhead at tropical latitudes
Not sure if that is helpful for you or not. It's a very small amount of light, not sure how 'visible' it is to the plant... Plus count in overcast nights in nature.
the point of this is to make my indoor grow as close to nature as possible with still having photoperiod control so i can veg and bud when I want.