I Am using a wista field 45dx. it has a fresnel in front of the ground glass (which is not gridded). I have noticed that there generally seems to be a small but meaningful variation in sharpness between my negatives (shows up in scans at ~2400) shot with the same lens at same aperture (usually f22). Ie i have what I perceive really sharp negatives and sometimes sharp but a little less so. I am using a 6x loupe, and I wonder whether my focusing is not critical enough, thus accounting for the difference. The loupe has adjustable focus, so I wonder exactly what i should use as a reference point in adusting to loupe focus, and what exactly i should be trying to get the image shap on, the fresnel ? The ground glass texture? Somewhere in between? The ground glass does have an etched mark for the 6x9, which I have been using as my loupe focus reference point...
Bookmarks