Nikon Nikkor-N 28mm f/2 pre-Ai ~ field flatness and "sharpness"

Ok.  Once more.  With feeling.  

... and continuing with the series of posts on field flatness and "sharpness" I'd like to take a look, this time, at a Nikon Nikkor-N 28mm f/2 pre-Ai lens.

Here is what Richard Haw has to say about the lens.   

Here is what the guys over at MIR have to say about the 28mm optic.

I picked this lens up off That Auction Site for a bit less money than they typically trade for.  Fearing the description might've left something out, I was pleasantly surprised to find the lens to be in very good condition.  Optically it appears mint.  So, in short, a win for the Home Team.  Or something like that.

Setup - 

• Sony A7 - ISO50, 2 second timer, in-camera levels used to square the whole plot up
• Manfrotto tripod - it's capable of securing an 8x10inch view camera, so it's sturdy enough for this
  
• Lens - Nikon Nikkor-N 28mm f/2 pre-Ai (updated with factory Ai aperture ring)
  
• Rawtherapee RAW to jpg conversion - Auto-Match function, but nothing further (ie: NO Capture Sharpening) to minimize processing effects
  

Comparison - 

Here is the scene setup.  You can see we have new curtains.  Life is good, isn't it?

 

 

[As always, click on the image and look at it to 100percent file size to see whatever there is to be seen.]

 

 

Comments - 

The Nikon Nikkor-N 28mm f/2 pre-Ai behaves similarly to all the Nikkor lenses I've looked at recently.  The field is acceptably flat from wide open, even if the extreme-extreme corners go slightly soft.  One click down and everything is good, even to the very edges.  By f/4 the under-corrected spherical aberration is gone and this lens is as sharp as anything modern.

You'll know what I'm about to say, of course.  Nikon designed their lenses to create a certain out of focus rendition behind the point of focus by designing into their lenses under-corrected spherical aberration.  With very few exceptions, this rendering is consistant across the line of optics from the start of the SLR era right up to the beginning of the advent of the autofocus days.

This is why I am no longer obsessed with "how sharp" a lens is wide open.  In general, wide open is where I get to see what was on the mind(s) of the lens designer(s).  That's where I've found lenses with "character" strut their stuff.

As for using this 28mm f/2, it's slightly bigger than its sisters 35mm f/2 Nikkor-O and 24mm f/2.8 Ai.  Yet it feels good to use, once I got over the impressive Sony A7 + adapter + lens length.  It's not for the faint of heart.  

The overall length observation is where I've wandered down many an old rangefinder lens path to see if there might be something good which might help keep the overall kit size to a minimum.  Alas, no.  I've not come across anything that renders the way these old Nikkors do.  Modern AF glass lack the characteristics of these old lenses, so there's little to no help to be found there, either.

Like the three!!! Nikkor 50mm f/1.4 I recently acquired, I'll have to work with the 28mm f/2 for awhile to fully sort out if I like it, or not.  At first blush, though, it does seem to be a very nice lens.  It fits very nicely between the easily scene distorting 24mm and the pretty but sometimes too tight feeling 35mm.

As I said in the last post, stay tuned.  Photos soon.