Quote Originally Posted by Donald Miller View Post
Whatever the correct term is, what I mean is that pt-pd and grade two Azo, for that matter, will require a camera negative with a greater density range than an equivalent grade two photographic enlarging paper. (1.65- 1.70 vs. 1.10 -1.25)
This is known as the Exposure Scale. It's the x-axis in your BTZS software.

Quote Originally Posted by Donald Miller
Yet when we examine the characteristics of prints made from optimally produced negatives, pt-pd will not have the dmax of a silver print. So if you have an explanation for that, I am open to hearing it.
This is the Density Scale -From Answers.com:
A value for the range density for a photographic material that corresponds to the difference between the maximum density and the minimum density. Also known as net density.

It's the y-axis on the BTZS software.

You're comparing apples and oranges when you ask that question.

The Azo and pt-pd paper have a low contrast, hence the greater exposure scale than greade 2 silver paper. Combine this with negatives that have a high density range, and you get a print of normal reproduction range.

The Azo print will produce the neg with greater d-max than the pt-pd, but the same range of exposure scale is recorded onto the paper. (By the way, my Ilford MG IV FB with grade 00 can print that same negative exposure scale range.)

I'm sure PE can explain the multiplication of negative and paper gradients/contrasts to come up with a normal reproduction range and how it applies to this question better than I...