Quote Originally Posted by wiedzmin View Post

thank you for explaining it. I think I'm getting it.

Do you mean several tests or you just know it and can do it in one attempt?
First time I always do a test of 5 developing times.

Test exposures on different sheets or few inches apart on roll film and cut them apart for different development times.

Later, as I go along, I just include a test exposure in with regular runs and "double check" what I was aiming for versus what I got.