Okay try this, place a frog on the ground, the frog jumps half way to a wall. The wall is the light source and the frog is holding a light meter.
In how many jumps will this take for the frog with the light meter to reach the wall which is the light source?

No matter how many jumps the frog is only half way there.
What is the reading on the light meter?

Sunny 16?