Looney 11 Rule
The lunar counterpart to Sunny 16: a full moon is correctly exposed at f/11 with a shutter speed of one over the ISO.
Formula / rule
t = 1/ISO at f/11
Measured in
stops (EV)
In depth
The moon is a sunlit rock, so it is lit by exactly the same source as a daytime landscape — it only looks dim because of the black sky around it. Meters are hopeless here, since the frame is overwhelmingly black and any averaging pattern will overexpose the disc into a white blob. The rule sidesteps the meter entirely.
Examples in practice
At ISO 100, photograph a full moon at 1/100 s and f/11 to hold the craters and maria.