I don't question the fact that it is possible to make prints in silver and in pt./pd. from the same D23 negative, or from negatives processed in D76 or HC110 for that matter. But regardless of whether you use D23 one bath or two bath the end result is a negative that has the same effective printing density range for both silver and pt./pd. so if you optimize development for one process it will be necessary to resort to some type of contrast control for the other. The point of dual purpose negatives is that you can print in both processes without having to use any contrast controls. Granted that the use of VC papers in silver and Na2 in pt./pd. makes contrast control a fairly routine operation but my theory is that it is best to always start with the most optimum negative for the process(s).
Originally Posted by Joe Lipka
BTW, if you look in Edward Weston's daybooks you will find that the knowledge that pyro negatives could be used for printing with both silver and pt./pd. has been around for a long time because at one point he comments specifically on this subject.
Last edited by sanking; 08-31-2004 at 11:27 AM. Click to view previous post history.