Attached is a summary of some of Richard Henry's acutance and granularity tests. I've also re-attached the "definitions" as a PDF.

I've included some of Henry's conclusions based on the data. I'm not saying I'm necessarily in agreement with him in all cases, and there are some questions I would have liked to ask him, issues to raise etc. One must keep the context of Henry's book in mind. He set out to prove or disprove technical assertions and claims made throughout the photographic literature since, as he correctly points out, for the most part we are asked to ignore research from companies like Kodak and instead rely on what people say even though they present no data, do not explain their tests, and often lack any scientific or even reasonable basis for their claims.

In all honesty I think the first half of the book dealing with print controls is more complete and better presented. The second half of the book - from which the attached data comes - leaves me with many questions. Nevertheless it highlights some important issues, and should make us think a little more critically when people say things like "Rodinal is sharp", or "D-76 is mushy". Do people know what sharpness is? Are their perceptions even honest or are they coloured by what they've been told is true? Etc.

Michael