Quote Originally Posted by Kirk Keyes View Post
Perhaps Donald is referring to the exposure range...

I hear people often (just this last weekend actually) say pt-pd has a "longer" tonal scale, much like they say that Azo has a "longer" tonal scale. They seems to be confusing either the exposure range of the paper, or they percieving something that is not backed up by math/physics/optics.
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)

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.