Film/developer testing

[EmilGil]

I've been thinking about doing a series of test shoots to try different films in different devs but I can't really decide how to do it. I got PanF+, APX100 and TriX (and some Fomapan100 coming in soon to replace the APX). For developers, I got PMK, Rodinal, Diafine and some Perceptol in the photo club darkroom. I know Diafine increases the apparent film speed about one to two stops while PMK and Perceptol are speed decreasing developers, downrating film speed 1-1.5 stops.

I read Kaiyen's blog article about determining EI but can you just leave out the dev time variable like that? I agree about finding the shadow exposure but I would have thought you should develop each frame for correct highlights at that specific exposure? Then I found this APUG post which I gather is about the same thing as Kaiyen's method, although Michel is using a generic motif and a slightly more advanced method of determining the zones. He then adjusts the dev-time after examining the roll. I feel I'm missing something here...

I know I should settle for one or two combinations to simplify the process but which ones? How do you guys go about testing a new film?

 

[Bryce]

I was taught to use Kaiyen's method also, but with two exceptions.
One is to use a spotmeter or something similar to establish some part of the scene that represents other zones, particularly zone 8 or 'detailed highlights'.
Once you've developed your negatives, you then print on your normal way, be that with a scanner or enlarger. Printing would be limited to the negatives that look close to right.
Kaiyen's method lets you establish the 'foot speed' of the film, but does not leave you with the data to determine whether you've over or under developed, and that is why knowing what zone 8 should look like is important.
So when you print the negative with the right foot speed, you should also get zone 8 to print as zone 8 with normal contrast. If you had to use hard paper to get zone 8 right on paper, you have under developed for your process, vice versa if it took soft contrast paper to get it to render right.
With hybrid processes, this will be a little harder to do- what is normal contrast?
I hope this helps.