Chemistry: On Futher Dilution Of D-23 And Lye

[Alan Johnson]

Henry p214 has "...sense of sharpness depends not only on acutance but also on adjacency effects...."

Controls in black and white photography : Henry, Richard J. (Richard Joseph) : Free Download, Borrow, and Streaming : Internet Archive

270 p. : 28 cm

archive.org

You propose to add "macro contrast, microcontrast, and resolution". Is there some source for this addition?

 

[MattKing]

Henry p214 has "...sense of sharpness depends not only on acutance but also on adjacency effects...."

Controls in black and white photography : Henry, Richard J. (Richard Joseph) : Free Download, Borrow, and Streaming : Internet Archive

270 p. : 28 cm

archive.org

You propose to add "macro contrast, microcontrast, and resolution". Is there some source for this addition?

A deep dive that I did into what people perceive as sharpness back a few years ago.
It originated with Ctein's "Post Exposure", and went from there.
The problem arises from the fact that the "macro contrast, micro contrast and resolution" components have mostly subjective affect - so while one could probably poll to measure them statistically, they are highly viewer dependent.
We have all seen examples of two images that are probably equally "sharp", but where many people find that one appears more "sharp" to them because of the lighting and drama and DMax ....

 

[chuckroast]

A deep dive that I did into what people perceive as sharpness back a few years ago.
It originated with Ctein's "Post Exposure", and went from there.
The problem arises from the fact that the "macro contrast, micro contrast and resolution" components have mostly subjective affect - so while one could probably poll to measure them statistically, they are highly viewer dependent.
We have all seen examples of two images that are probably equally "sharp", but where many people find that one appears more "sharp" to them because of the lighting and drama and DMax ....

I stipulate that you are right, but isn't that really true of all human perception?

How "sharp" a print is depends on many things among which include viewing distance, edge transition deliniation, contrast, perceptible grain. acuity of the taking lens, the film itself, and the developer/agitation method. The only thing you can do it hold all but one of these constant to see how varying that one thing affects perceptual sharpness.

In my youth I did research on how people hear in noisy environments. The most important thing that research taught me was that - when dealing with human perception where both the sensing organ and brain play significant roles - if you find any correlation at all varying something, it's typically just out of the statistical noise floor. Humans themselves vary so very much. And give up any hope of finding causality except in the most gross situations.

Oh ... the other thing I learned was that doing an experiment properly is very difficult to do.

 

[MattKing]

I stipulate that you are right, but isn't that really true of all human perception?

It is, but as I was responding to your comment about acutance having "two meanings", I thought it useful to mention where people find the "meaning" that they use.

 

[chuckroast]

It is, but as I was responding to your comment about acutance having "two meanings", I thought it useful to mention where people find the "meaning" that they use.

Not my comment I don't think but your point is taken