Nikon Cf 4x / 0.2 Plan APO Finite Objective

I've been searching for a long time for a nice quality example of this famous Nikon 4x objective. As Mark Goodman states in his review, "this lens is the standard by which all others are compared in this magnification range".

You can read Mark's review at:

http://coinimaging.com/nikon_4apo.html

As a test of this objective I took a picture of a 1955-S RPM#1 from a group of 7 I found in a recent roll search. The objective performed every bit as well as expected. Here is the image:



Note that this image is better, but not tremendously better than what can be achieved with a 0.13NA or even 0.10NA objective. Its higher NA (0.2) makes it sharper, but it also means more shots are required for the stack. The image above required 31 shots!! A 0.1NA objective would require half or fewer shots, but each one would be a little less sharp due to the smaller aperture causing diffraction.