Sony 35mm f/2.8 ZA compared to Nikon Nikkor-O 35mm f/2 ~ part Two

I'm still pixel-peeping until the eyes go bloodshot.  I can't help myself.  I'm addicted to trying to understand differences between different optical designs and implementations and I'm between photo-opportunities with way too much time on my hands.

I noticed something just as my eyes were going bloodshot.  It concerns the edges of the field of the Nikon Nikkor-O 35mm f/2 pre-Ai that I have.  Yes, they are soft.  

Shortly after I noted the edge softness Thom posted an article that asks the question of "Do lenses have character?"  I found it a rather interesting history of lens design and its evolution.  

Something that caught my eye was his comment that "...a common thing I observe in lens characteristics, and one of the things that forms my use of the "old school" shorthand: the older the lens design, the less likely it performs well as you move closer to the corners..."

Indeed, one of the things I see at the edges is that the softness includes chromatic aberrations.  Unlike in 1971 when this lens was manufactured we now have software that can "correct" for this kind of aberration.  Might cleaning up the chromatic faults help make the corners appear sharper on this "old school" lens?  Here's my look at it.

 

As background, I'm still trying to figure out with of the last Nikon Nikkors I'll keep as my "just in case" lenses.  Not yet sure if I'll keep the Nikkor-O, but it does have some things I like about its rendition, so for now it'll stay in the Toy Drawer.

Setup ~ 

• Camera - 
• Sony A7
• Lenses - 
• Sony 35mm f/2.8 ZA
• Nikon Nikkor-O 35mm f/2
  
• Bogen tripod
  

• RawTherapee to snug up the curves, with and without chromatic aberration corrections and Capture Sharpen
  

Comparison ~

As always, click on the image and enlarge to 100percent to see whatever there is to be seen.

 

Comments ~

As I previously said, without Capture Sharpening the Nikkor's edges never really clean up, though I can see that stopping down does help edge performance in the old lens.  Capture Sharpening the Nikkor-O at the edges begins to look decent starting at f/4 and looks pretty good at f/5.6, but it never ever comes close to that more current Sony 35mm f/2.8 ZA.

Using RawTherapee's "Chromatic Aberrations" sliders, I moved them until the image looked "good" to my eyes.  It didn't take much, +0.003 or +0.004 depending on the aperture.

At f/2 and f/2.8 the chromatic aberration corrected images don't look all that much better than before.  The differences are subtle and take a bit of study to see.  At f/4 and f/5.6 things are coming a little closer to the Sony 35mm, but are still a bit away from the ZA's sense of perfection.

In the case of this Nikkor-O I really haven't added much to Thom's conversation other than to confirm this lens' edge is soft at wider apertures.  Maybe the lesson is in situations that demand it to stop down to f/4 to get it to behave more fully up modern lens standards.