What a Difference an S Makes ?

Intro

Do you have a go-to lens, the single lens that’ll cope with most of your shots, doesn’t get in the way and just makes a great job of it when you need it to ? I do, and it’s my Nikkor 28mm f2.8 AI.

The thing is though, all the while I’ve been using my go-to lens, I’ve known there to be a supposedly better version of this lens out there, and that knowledge had eaten away at me. So this Christmas I gave in and ordered myself the better version, what’s this lens called ? The Nikkor 28mm f2.8 AI-S, wowee, sounds like a big leap forward right ?

What’s the difference then, well in size and weight you would notice little or no difference, the majority of the changes are inside. Excuse my crummy hand drawings, but below are diagrams showing the difference in design.

On the left the AI version, with the AI-S on the right

On the face of it, it’s a 7 element 7 group design vs an 8 element 8 group design, but there’s more to it than that. The new central elements that were added are floating elements, allowing for better focussing at all distances, with a particular benefit at close range, the new lens could now focus right down to 0.2m, an improvement over the previous 0.3m close focus distance. Nikon named this innovation CRC or close range correction.

In addition lens coating were improved over time, with the final iteration of the AI-S receiving SIC, or Super Integrated Coating. A green coloured multi-coating to help reduce ghosting and flare over a wider wavelength range than available previously. The SIC coating was applied to the AI-S lens with serial numbers of 825XXX and above.

Having said that the size and weight are pretty much the same, I have read in forums etc., that the internal build quality of the AI version is superior to that of the AI-S, with more plastic being introduced over the length of the production run, although without dismantling the lenses I would find that difficult to confirm. However, given that my two copies are separated in age by 25+ years, then it’s difficult to imagine that the younger lens will be any less reliable.

So what was I hoping for by obtaining the newest version of the AI-S ? Well, even better detail, closer focussing, reduced flaring and maybe some better contrast with the new coating.

Testing

So how did it do ? Let’s take a look at some examples from my first roll. I shot a couple of rolls of Ilford Delta 400, with the AI mounted on an FM2N, and the AI-S on an FM3A. I took paired shots with no filters, developed in D-23 for 7 min 30 secs, scanned by DSLR and simply processed with Neg Lab Pro with no adjustments made in post.

The AI shots are on the left, and the AI-S shots are on the right. Move the slider to the left to view the AI-S shot, and move the slider to the right to view the AI shot.

A backlit scene, not easy to tell the difference, but more contrast on the AI-S shot

As above, set-up shots for the following close ups.

Demonstrating the closer focus ability of the AI-S

Outdoors, into the sun, the AI-S has better flare resistance.

Indoors, with a light source from above, the AI-S demonstrated a distracting and unusual flare.

What seems like improved contrast and detail with the AI-S

Similar to above, re contrast and detail.

Summary

Closer focussing – tick

Better detail – tick

More contrast – tick

Flare – a mixed bag

So the AI-S seemed to perform better in three out of the four requirements, even with some swings and roundabouts regarding flare, it’s arguably a better lens than the AI. In my mind, not by much though, I think the only attribute that really stood out was the close focusing, focussing to 0.2m was surprisingly close in practice, and felt like more than a 0.1m difference between the two lenses.

The AI-S version of the Nikkor 28mm f2.8 sells for around £250, particularly if you want a nice example with a late serial number for the SIC. While the AI version can be had at half or even less than that price.

So is it worth paying that much more for the AI-S and it’s close focussing? In my opinion, it’s not worth it, the AI is a real bargain I think, and 0.3m is not bad at all for close focussing. I have to admit I was tempted by all the nice reviews of the AI-S, and so eventually took the plunge, when really I should have listened to what my gut told me, the AI version just takes beautiful photos, and is a great all rounder.

© Copyright owner Steve Starr. First publication 7th January 2023