Quote Originally Posted by Stephen Benskin View Post
7 1/3 is larger than 7, so shouldn't 7 1/3 have a larger NDR? Just to be clear, this is not just a simple case of different methodolgies. The paper LER is the basic method to determine the aim negative density range for a paper. A NDR of 1.25 simply will not fit on a LER 1.05. The only possible explanation as to why the Zone System 1.25 target density range determined from testing is able to print on a grade 2 paper with a LER of 1.05 is because of the addition of flare (which is not factored in with the testing) in normal shooting conditions. Remember in camera Zone System testing has minimum to zero flare.
Oh I got the counting of "towels and clothespins" wrong. They're both essentially 7 stops for normal, let's make them both 7 and ignore the 1/3 until reason forces us to hunt that down. The sheet you gave me highlights 7 stops for normal.

On the next page of The Negative, Adams mentioned the tendency of manufacturers to make papers a bit "shorter scale" for Grade 2 (so you better test for yourself), he also qualified his numbers as being what works for him. And many photographers are using variable contrast paper (which makes it less important to get it right).

But here's where the flare is: The enlarger lens.