Lens Stories ~ Nikon Nikkor 85mm f/2 Ai

OK.  So I broke my own self imposed budget limit.  I couldn't help myself.  I'm sure I could justify the purchase based on non-budgetary criteria.  My fuzzy little mind remembers wondering how Nikon's successor to the 85mm f/1.8 H, HC, K lens performed behind the point of focus.

I'd read that the 85mm Nikkor f/2 was a "boring" lens.  Sharp(ish) wide open and nothing special by way of its out of focus rendering.

I owned a pretty Nikon Nikkor 85mm f/2 Ai when I first moved to Europe.  But it was sold in a fit of "downsizing" the photographic tools cabinet.  Slowly, over the years, I came to regret the decision.  So when this lens came up at a somewhat reasonable price, my 50Euro per-lens budget cap went out the window.


Being one to not trust what's posted on the 'net, I decided to have yet another look at this lens.  Here is what I found (confirmed, yet some more?, oh gawds, the Insanity continues).

The Nikon Nikkor 85mm f/2 Ai is very slightly sharper wide open than any of the Nikon Nikkor 85mm f/1.8 H, HC, or K lenses that I've owned.  By f/2.8 my eyes can't see any difference in "resolution" between the two lenses.

Looking at behind the point of focus rendition I see that the f/2 lens is much more neutral in it's correction of spherical aberration than the f/1.8 lens is.  Perhaps it is this characteristic that some people find "boring?"  I wonder.

In any event, the f/2 lens has shallower depth of field wide open than it's f/1.8 sibling.  This has a lot to do with how the out of focus region spherical aberration is treated.


Standing back a bit and looking at the two lens designs, I can hazard a guess or two about their performance trade-offs and design details.  Perhaps the most obvious is this.  The f/1.8 H, HC, K lens is a wonderful portrait lens in the old style.  The lens designer gave that lens a subtle, beautiful behind the point of focus rendition.  Highlights positively "glow" and it reminds me in some ways of a lovely Wollensak Verito large format optic.  The complement to the older 85mm lens, in my mind, is the lovely 50mm f/1.8 Ai/AiS.

The Nikon Nikkor f/2 Ai lens, on the other hand, feels well corrected.  It could be a good companion to the Micro-Nikkor 55mm f/3.5 pre-Ai and f/2.8 Ai and Nikkor-O 35mm f/2 lenses that I tend to shoot with.