Quote Originally Posted by Gregg Brekke

If I want to continue to use PMK Pyro with JandC Classic 200 rated at 200 are there any practical tips out there? Has anyone tried the following:

The answer is no, and in fact you won't be able to get that much effective film speed with Pyrocat-HD either.

Effective film speed is largely a property of the emulsion for development to a given contrast range. In other words, increasing time of development from 14 to 20 minutes may result in more effective film speed, but it does so at a considerable increase in negative contrast. This will be true of all developers.

The fact of the matter is that JandC Classic 200, and Fortepan 200 as well as Bergger BPF, which are similar if not identical films, have in fact an effective film speed of much less than 200, closer to 100 in fact, when developed to a density range of 1.05 for silver printing. In my own tests of this film, which have been conducted with sensitometry ( as opposed to the "eye-balling" procedure) I have found that the effective film speed is about 100 with PMK and D76 1:1, and about 120 with Pyrocat-HD.

As a general rule developers that contain phenidone produce slightly more EFS than those that do not, and this explains the slight increase in film speed you get with Pyrocat-HD over the other two developers. You might get slighthly more effective film speed with a formula like FX 37 (which also contains phenidone and is about tops in the area of speed enhancing) but I very much doubt that even with this developer you can get an EFS with JandC 200 of much over 140 when developing for the negative DR of 1.05 needed for silver printing.

Photographers who need to develop their negatives for a longer period of time to reach the high contrast needed for printing with alternative processes can rate the film for an EFS of about 200.

Bottom line is this. If you really need an EFS film speed of 200 for silver printing you need to use another film. Changing developers or increasing time of development won't get the job done, unless you are prepared to live with negatives of much higher contrast.

Sandy King