You got it right, perceived sharpness is a tricky thing. Resolution is only one of the components. There's also edge acutance, contrast/micro-contrast and graininess. And of course the size of the original negative. High quality reproductions often appear to me to have enhanced micro-contrast, a kind of subtle unsharp mask effect. I'm no expert on the process, but it seems to me somewhere in those laser scan duotone or tritone processes you end up with that. Not an overt effect, but just enough to give a heightened impression of sharpness. It seems to me to have less to do with the reproduction ratio, as I have always seen the same thing even in fairly large reproductions such as those on some Ansel Adams posters, etc.
Originally Posted by batwister
Anyhow I guess this was getting into a whole other complicated topic. Just thought it was worth throwing out there as something else to keep in mind because I remember when I finally saw original prints by Ansel, Weston, Sexton etc, as beautiful as they were, even contact prints did not have quite the crystal clarity I knew from the books.
All that aside I think you're on the right track in trying to identify and address the various variables (negative stage, lens and baseboard alignment, negative flatness, lens quality, vibration, focusing). Here are two more to keep in mind (although #2 is only if you're really nuts - like me): 1) Possibility of focus shift when stopping your particular lens down. 2) Quality of the carrier glass, particularly below the negative.