In Dick Arentz's book "Platinum and Palladium Printing" he published data for use with FP4 and D-76 to yield a negative with a density range of 1.4. I tried to use these numbers, but they were way off for me, and I'm curious as to why.
He uses subject brightness range, and if I understand, that is BTZS nomenclature, which I'm barely familiar with. I use 5 stops as a normal range, whereas he considers SBR 7 a normal negative. I meter the deepest shadow and call it zone III, then place highlights on zone VIII for a N negative.
How far off are the numbers for me? Well, I tried developing a N negative for the recommended 12 minutes at 1:1. On the densitometer I could only get a highlight of about 1.5. Not even close. After a number of trials, I found that if I use D-76 straight, I need to develop for 16 minutes to get a dense enough highlight for the pt/pd process, and a 1.3 or 1.4 range. On Dick's chart (attached) that development represents more than a plus-one.
All of this is OK with me, because it's the result I'm after, and if it takes 16 minutes, I'm fine with that.
My question is simply how does one explain such a dramatic difference between my numbers and his? What would I need to do to make his numbers work for me? Doesn't 12 minutes at 1:1 seem short and weak for the densities we're looking for?
It's an excellent book, by the way! Thank you for considering my questions.
Bookmarks