middlecalf said:
Other sources indicate that pyro developed negatives can't be measured properly with a densitometer. Does this method suffer similarly?
First let it be said, this ain’t rocket science! I gave that up when I retired. This is a quick and dirty method of checking my technique especially in light of all the “new” products coming out and the demise of some of my favorite “oldies” forcing changes.
I have no data regarding staining developers. The Minolta spot meter has a pretty good response to colors excepting deep reds for example. It has no “correction” such as the Zone VI reworked Pentax but the very basic measurements I have made “around the house” indicate a rather linear response to the photographic spectrum overall.
The problem is, how can one translate readings to the final paper product? My work on this aspect is ongoing. So far, without a reflection densitometer, it has not proving easy. I make a contact print on the medium I will use for the final product and scan it with the mate’s computer equipment. Using the “dropper” tool in Paint Shop Pro, I determine the average gray scale level of the areas of interest and compare the reading(s) with the max and min density areas graphically.
So far this has not yielded a reliable match. The shapes of the curves are quite comparable but what does that mean? There are too many variables in the print system. If I can clean up the process…. Oh, the heck with it! I am only interested in the relative scale of my negatives. If the gray scale I determine in the negative correlates with my expectations I’m happy. If I have done something wrong, this method will "expose" it (puns: don’t ya hate ‘em) and indicate a "solution", e.g., pyro instead of D76.