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Robert --
I'm sorry to say I don't do materials' tests except for the purpose of illustrating articles or providing working data to bundle with the BTZS ExpoDev and Plotter software. The View Camera Store offers a testing service; their email address is: info@viewcamerastore.com.
You've raised a lot of issues here and I'm not sure just how to deal with them in this limited forum format. Your process description indicates a commitment to the traditional Zone System philosophy and methods and that poses a problem because although the ZS and BTZS both exist for the purpose of helping serious photographers use this medium more effectively and, hopefully more creatively, the concepts and procedures are very different. For that reason I'd strongly suggest that unless you're willing to consider accepting major changes in approach and procedures, you'll be better served by sticking with the Zone System. I'm afraid that attempts to incorporate bits and pieces of BTZS thought and data into the traditional ZS framework will be counterproductive.
We can discuss this further if you want to but it will be helpful if you've read my book and/or the pertinent issues of D-Max, the quarterly VCS newsletter. In the meantime, here are responses to your attachment questions:
-> Yes, Emin and Emax stand for Minimum and Maximum test exposures
-> "Real pictorial image" is not really what I meant to say; SBR refers to the luminance range of the subject — presumably (although not necessarily) a pictorial subject.
-> G-bar stands for the symbol "G with a bar above it" which stands for "average gradient." "G" alone stands for "gradient" which refers to the slope of a characteristic curve. Then "average gradient" is average slope, measured between any two chosen points along the curve.
-> The ISO Standard specifies that the ISO speed of a film be derived from the exposure required to produce a negative density of 0.1 over B+F when development is such that an exposure range of 1.3 results in a density range of 0.8. The gradient value "0.62" is not mentioned in the Standard but 0.8/1.3 = 0.615 which is close enough. Kodak's Contrast Index is a proprietary method of locating the speed point on a film curve; in the most common version, finding it requires a simple tool or template.
-> The ISO speed of a film may or may not represent the film's real speed in use. Kodak (and others) refer to a practical working speed as an "Exposure Index;" we call it an "Effective Film Speed" and I believe you've mentioned a "personal film speed" which is about the same thing.
1. See my recent response to David Mark's query about flare testing. The program assumes an "average" amount of flare effect and relates it to subject range. This value is user-adjustable so it can be changed for each exposure or set at some average setting and left there. It's up to the user to decide.
2. A paper's Exposure Scale value is the number that the entire process, from metering to negative developing, aims to accommodate. Presumably you will determine that value for yourself by a quick paper test.
Again, I suggest that you read my book; all of these things are explained at some length there......I think!
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