Indeed. I was torn on how much information to put in this summary. Henry is quite thorough in his detailed descriptions of the equipment, procedures (including comparisons to those of Kodak and others), and statistics (he was an analytical chemist after all), but a description of the microdensitometry alone would require a few pages and to detail the experimental methods properly I'd have essentially had to recopy tens of pages.
One thing which comes up repeatedly - findings essentially in agreement with Kodak. It is important to note he did not approach the excercise with the intention of proving Kodak or Ilford or Agfa wrong. In fact it would be surprising if his results differed wildly from those of reputable scientists and were in conflict with good theory. What he wanted to do was test the claims and assertions made by other people in books, magazines, articles and such. In general throughout the book he's quite good about comparing his findings with those of Kodak and other researchers, and then using all this to test the validity of statements made by others.
It is a book about applying proper scientific method to darkroom photography, since unfortunately this is almost never done by the people who often speak loudest. Where the book is less successful is the theory. The data can often show a claim to be true or false, but explaining why is another matter. That is not the primary focus of the book and Henry freely admits when he is unable to explain why something is the way it is. This is why I find the first half of the book about printing controls "better" than the stuff about film and developers. When it comes to printing it is easier to test the validity of many things that are said. When it comes to film processing on the other hand, things can get very complicated from a theoretical perspective. I think I would challenge a few of his interpretations of the data.
There are also still a couple of things I don't fully understand about his use of the acutance formula. This is also something I'm a little unclear on in the Altman/Henn study. The formula is still bothering me. It is assumed to NOT take edge effects into account, but then there's that Dmax-Dmin part of the equation... It's like "half pregnant".
A shame he is not around. While it isn't perfect, I think many people could learn a lot from his book. I wish I could carry on that type of work.
Last edited by Michael R 1974; 07-02-2013 at 07:18 PM. Click to view previous post history.