> Both lenses don't share the same optical design?
They are the same block diagram, but a different "prescription". The glass and curvatures of the elements are different. The Nikkor has more harsh Bokeh, higher contrast, and I believe less field curvature.
The Nikkor 5cm F1.4 changed it's "prescription" after the first couple of batches. The diameter of the elements was increased. i learned this by taking a couple of them apart to repair a badly dented front ring. The glass of the 1950 Nikkor passed through the front mount of a 34x mount. The entire mount and all of the optics were about 1mm less in diameter. The change-over occurred somewhere in the early "made in Japan" lenses. I suspect it is when the S2 was in development, and the 24x36 format was scheduled to replace the 24x34 format of the Nikon M and Nikon S.
The post-war Sonnars also changed the formula, used newer glass. The Zeiss-Opton optics will not fit into a J-3 mount, the design of the mount changed dramatically. The post-war CZJ 5cm f2 optics module did not fit into a J-8 mount. Successes so far are with collapsible 5cm f2 optics modules in J-8 mounts, and pre-war CZJ 5cm F1.5 in J-3 mount.
Last edited by lens_hacker; 08-09-2008 at 08:17 AM. Click to view previous post history.