My approach to zone system testing is based on the writings of Phil Davis in his book Beyond the Zone System. I like this method for testing materials because it gives you a great deal of information without the need for retesting.
In this section I do not intend on explaining my testing methods. Instead, I am just showing the outcome of my tests and the basic information that I use when applying the zone system. Please do not assume that the information that I give will work for you. If you find that you are using the same materials and developing methods, then the information here could be used as a good starting point for your own tests.
The information outlined here will be for Kodak’s T-Max 100 and T-Max 400 in the 4×5 film size. Kodak has recently made minor changes to T-Max and slight changes in development are required. I develop most of my film in BTZS tubes. In the past I have used the JOBO system and it is a great way to develop film. I have found that for my personal work habits the BTZS tubes work well because I can develop each sheet of film differently than the rest of the batch in both time and developer choice. After an average day of shooting, I will usually enter the darkroom with 10 or 12 sheets of film and each sheet may require different development times and developer dilutions so the BTZS tubes work well for me.
Click here for a good overview of using the BTZS tubes . My use of these tubes is very similar. I use water for the stop bath and I use Photographers Formulary’s TF-4 Fixer. I use the fixer in a tray in which I have created dividers to keep six sheets of film separated, this helps to insure that the film is not scratched in the fixing stage. I like the TF-4 fixer for T-Max films, I have not found the need to use the double strength hypo clearing agent as described in the overview of using the BTZS tubes.