OK. Now that I have had a chance to do a couple of test shots– wide open at f11, Tmax 320, Sprint dev.– 5 copies of a test pattern pinned to the wall in a cross pattern, so that the papers fill the frame. I can say that any difference between how the elements were spaced when I bought the lens and the specified distance from the above post is invisible on the negative using an 8x loupe - right to the corners. Since I will be contact printing anything I shoot with this lens, that's more than good enough for me.

Damn, this thing is sharp! I'm used to shooting with old brassies and the occasional magnifying glass and such. I might have to up my game in terms of focusing... . The thing is that I bought it on a whim, being flush with the money from selling off some 35mm gear. It doesn't fit my "travel" 8x10- needs too much bellows draw for the Korona Home Portrait. I may put it up for trade for something in the 12-14 inch range in shutter, but it is amazing at long portrait range on the Studio Master.