I guess that's the problem. Even in the thread Alan linked to, it's about 99% nonsense, especially once you get Rodinal and staining/tanning people involved. But I suppose I'm differentiating actual sharpness from characteristics that can enhance the impression of sharpness. Edge effects, for me, fall under the latter category. With a given resolution, acutance (excluding edge effects) has mostly to do with the film itself and exposure, so turbidity, emulsion layers and thickness, homogeneity, acutance dyes, anti-halation and other things. Then there is the exposure itself, which of course causes some degree of irradiation etc. depending on the film characteristics. These things determine the actual acutance. I don't think developers can do much with that. I think they mostly influence graininess (as evidenced in the Altman/Henn study), and to some/varying extent edge effects. And I also think when people see pronounced grain they see sharpness.
Originally Posted by Photo Engineer
I also agree in the end generalizations are tricky. The Altman/Henn study and Henry's tests showed this. Who would ever expect stock D-25 to be sharp? Well it certainly seemed to do just that with Panatomic-X.
Another question (ultimately in relation to the sharpness/grain masking claims made by people formulating tanning/staining developers). I think I remember reading somewhere in Haist (can't seem to find it now though) about additives in colour emulsions to prevent dye spreading - in other words to keep the dye from forming too large a cloud around the silver. Am I dreaming that up or is it real?