U of S | Mailing List Archive | alt-photo-process-l | Re: pt/pd stops

Re: pt/pd stops

Chris wrote:

Can someone tell me the greatest amount of stops they have gotten with pt/pd? Or put it in terms of logs or DR, if that's how you do it.
I use the traditional formula, 100% Pt, no contrast agent, and you can clearly see all 31 steps of a 3.05 wedge on the very smooth, very white papers I favor. That is the exposure scale, of course -- the print Dmax is generally 1.5 or so. I usually make negatives with a DR of 3.1-3.2 for this process (which limits one's choice of films).

Best regards,


  • References:
    • pt/pd stops
      • From: "Christina Z. Anderson" <zphoto@montana.net>