Quote Originally Posted by ROL View Post
Even said twice, I don't understand you. How does "proportional" time increase make more sense, again?
More commonly called f/stop printing.

Instead of making test strips exposures 5, 10, 15, 20, 25 seconds, make them in f/stop related increments.

For example third-f/stops: 5, 6, 8, 10, 13 seconds.