noseoil said:
Tom has given you the best advice here. It is sort of like asking someone if they can "borrow" your wife and then return her after they are finished. My suggestion would be to get the BTZS book by Phil Davis and have at it. The zone system's N, N+ and N- numbers will not tell the whole story about exposure and development. Because of the paper's scale and the film's speed, numbers can change with respect to development times.
Best place to start is to look at existing film curves and then the numbers which someone like Sandy King has been so kind as to publish. With a little bit of tinkering, you will be able to figure it out on your own. Plan on about 6 months to have a system which works well, a few sheets of paper and some film. tim
The BTZS type data that I provide is derived from a specified type of agitation, always rotary in BTZS type tubes unless other wise specified. I sometimes give results in CI, or Average Gradient, at other times as SBR values based on a desired negative DR. If you follow the same development procedures that I use your results should not be very different from mine in terms of CI or SBR. In that sense the data derived from BTZS testing is highly portable.
However, people on this forum are using a wide range of processes and most of them have very specific requirements in terms of what kind of negative is required. My own specific data would be useful to someone else in terms of process application only to the extent that they understand what kind of CI or SBR at a given negative DR is required, and of course how to measure it.
As a general rule I would venture the opinion that if you develop your film with rotary processing and print with graded silver papers (including AZO) or one of the UV sensitive alternative processes you will find my film development recommendations to be a very good guide that in most cases will need adjustment by no more than about 1/2 grade in contrast to be spot on.
That would not be true, however, if you are using VC papers because the spectral density requirements of stained negatives varies a lot according to the color of the stain and the actual sensitivity of the paper. More exotic types of development, such as minimal, semi-stand and stand also will require experimentation because small changes in dilution or frequency and type of agitation can have a big impact on the final result.
Sandy
