AI superior to AI-S?

[Bjørn Rørslett]

Well, one learns something new every day. Good to know I don't need to worry about this issue, though.

[Akira]

The optical change prevented us CPU-modifying the lens we had planned, so was significant.

Nikon have a very long tradition of keeping the playing cards tight to their chest. A lot of the improvement are never published.

Maybe.  But Nikon wouldn't have imagined that both you and Erik had jokers: chipping MF Nikkors.   

[Bjørn Rørslett]

Nikon simply claims the chipping is "impossible", even though they have produced such lenses themselves ....

[John Koerner]

Thank you for all the responses.

Specifically, the lenses I was interested in were the 24mm f/2 and the 58mm f/1.2 Noct.
(The new 28mm f/2.8 AI-S actually has a longer focus throw that any of the elder iterations, including the f/2, and is one of my two favorite wildlife lenses, period, because of its ability to get so close to a subject as well as to reverse-mount for 2:1 macro.)

Of the lenses mentioned, I have been considering purchasing a 24mm f/2 as a midway point between 20 and 28, and for macro work I prefer manual focus, and will mostly use this as a reversed-lens in a studio setting.

I have been rubbing my chin also with respect to owning a 58 mm f/1.2 Noct, and (if I decide to pay the obscene price) will mostly be using it on a tripod, focusing from a Live View situation. Even hand-held in a street situation, I believe I would prefer the longer focus throw. So, unless otherwise advised (for the "internal" reasons hinted at), I think I would prefer the AI version of the Noct, for its substantially-longer focus throw, and would be willing to give up 2 aperture blades in favor of the more precise focus control.

However, I also noticed a little-mentioned lens, the 55mm f/1.2, which is between the focal lengths of the 50mm f/1.2 AI/AI-S, and the 58mm f/1.2 Noct. AI/AI-S ... and yet the 55mm AI has the same focus throw of the 58 mm Noct (230°).

I'm curious as to whether anyone has conducted any sort of test comparison as the qualitative difference between these two lenses, the 55mm f/1.2 and the 58mm f/1.2 Noct, as they were both manufactured around 1977, with the 55mm coming and going rather quickly. (I am imagining the 55mm was cheaper, and likely a direct competitor, to the much more expensive Noct., offering virtually the same features.) Haven't heard much talk about it though ...

Thanks again for all input,

Jack

(PS: I have no intention of chipping any lens.)

[Akira]

John, have you considered Cosina/Voigtänder Nokton 58mm f1.4?  It is said to be a fine performer (I haven't tried it myself, but our member Airy adores it) and the latest 3rd generation model has the focus throw as long as that of the 50mm Ai lenses.  Also, they are chipped.

[John Koerner]

John, have you considered Cosina/Voigtänder Nokton 58mm f1.4?  It is said to be a fine performer (I haven't tried it myself, but our member Airy adores it) and has the focus throw as long as (or perhaps a bit longer than) the 50mm Ai lenses.  Also, they are chipped.

I have, actually, thank you.

At this point, I am romantically-involved with old Nikon lenses (lol), but I do enjoy my Voigtänder 125mm macro ... so if I "cheat" and stray to another brand, another Voigtänder would head the list of possibilities. (In fact, I think I asked about this lens on another thread somewhere.) So thank you for the suggestion, and I may well go this way, ultimately.

However, right now, I have a "collector's inch" to accumulate elder Nikkor lenses at this time

I just want to narrow-down the best choices for my objectives 

[Bjørn Rørslett]

I would strongly warn against using the 24/2 reversed for quality results. That really is not what the lens was designed for and results are likely poor. Chromatic and spherical aberrations will be quite visible.

The 24/2 has had a mixed acceptance and many find it not very good in optical performance. I concurred to the mediocre reputation with the first 2 or 3 samples of this lens, but later found a very nice one that performed much better. However, after a while its performance also deteriorated. Turned out as a likely explanation this lens has a CRC design in which the rear group easily works itself slightly out of proper position leading to mediocre rendering. Once that issue was addressed, the lens again performed well.

Do note that even a good sample of the 24/2 may require CA removal for images to display their best.

[jhinkey]

Most Nikkors have participated in a slow evolution and improvement over the years. The AI/AIS divide is not always the most important step in this process. Thus one has to be careful when comparing lenses of different vintage lest the comparison is flawed due to other internal changes, not just focusing throw.

Yep, some cases in point:
105/2.5 AI - 7 curved aperture blades, no built in hood
105/2.5 AI-S - 7 straight blades, yes build in hood
28/2 AI - 7 curved aperture blades
28/2 AI-S  - 7 straight aperture blades

All depends if curved vs. straight blades or built-in hoods or not are meaningful to you (for these lenses)

For me I like built-in hoods, though I've been annoyed at the Bokeh at f/4 with point light sources in the background for the 105/2.5 AI-S that I have.
Love the curved blades of the 28/2 AI . . .

[Erik Lund]

The old 55mm AI 1.2 is the forerunner for the 50mm 1.2 Ai and Ais and performance is very similar although they are optically very different. Central sharpness and general low light lenses.

The Noct-Nikkor 58mm 1.2 is optimized for central sharpness and low coma and is superior in Bokeh, a true dream lens that is really fun shooting, we have some nice threads here with loads of images, the 58mm AFS 1.4 is very close in performance and so is 35mm AFS 1.4 although the 35mm works quite well stopped way down,,,

The internal design and build of the 58mm Ai is just so nice and the aperture opening is pretty round around f1/8-f/2.2 or so even though it's a 6 bladed lens, as indicated on Rolands pages.
Ais version just has less helicoil length that's it,,

Small variances can be found for Nocts since it's a hand grinded aspherical front element and pretty much a hand build lens, rear element is fused into place at the rear - Also plenty of images here for that ones internals.

[Erik Lund]

As a curiosity the 50mm f/1.2 Ais that Bjørn has got a Dandelion Heart transplanted into the F-Mount itself, one of brighter chippings IMHO.

A very durable solution.

Otherwise I strongly prefer to chip with the original Nikon CPU contact blocks and the custom CPU prints from Bjørn as opposed to the rather flimsy Dandelions,,,

I believe we have chipped several hundred lenses, and only one or two fatal issues ever as far as I know.

[chris dees]

As a curiosity the 50mm f/1.2 Ais that Bjørn has got a Dandelion Heart transplanted into the F-Mount itself, one of brighter chippings IMHO.

A very durable solution.

Otherwise I strongly prefer to chip with the original Nikon CPU contact blocks and the custom CPU prints from Bjørn as opposed to the rather flimsy Dandelions,,,

I believe we have chipped several hundred lenses, and only one or two fatal issues ever as far as I know.

Is a Dandelion a viable option for the Nikkor-S.C 55/1.2 as well? 
I guess you understand why I'm asking. 

[Bjørn Rørslett]

A risky business if it is even possible. My gut feeling is 'no'.

[John Koerner]

I would strongly warn against using the 24/2 reversed for quality results. That really is not what the lens was designed for and results are likely poor. Chromatic and spherical aberrations will be quite visible.

The 24/2 has had a mixed acceptance and many find it not very good in optical performance. I concurred to the mediocre reputation with the first 2 or 3 samples of this lens, but later found a very nice one that performed much better. However, after a while its performance also deteriorated. Turned out as a likely explanation this lens has a CRC design in which the rear group easily works itself slightly out of proper position leading to mediocre rendering. Once that issue was addressed, the lens again performed well.

Do note that even a good sample of the 24/2 may require CA removal for images to display their best.

Appreciate the heads-up, thanks.

[John Koerner]

Yep, some cases in point:
105/2.5 AI - 7 curved aperture blades, no built in hood
105/2.5 AI-S - 7 straight blades, yes build in hood
28/2 AI - 7 curved aperture blades
28/2 AI-S  - 7 straight aperture blades

All depends if curved vs. straight blades or built-in hoods or not are meaningful to you (for these lenses)

For me I like built-in hoods, though I've been annoyed at the Bokeh at f/4 with point light sources in the background for the 105/2.5 AI-S that I have.
Love the curved blades of the 28/2 AI . . .

Interesting distinctions, thank you.

It is for these subtle differences that I made this post

Would for sure go for the 28/2 AI, except that my 28/2.8 has even more focus throw ... and reputed to be the better of the two, reversed.

[John Geerts]

Not mentioned here but I find the AIS version of the 300mm/4.5 ED-IF better than the AI (ED-IF)

Another perhaps valid follow-up question:  Is the last Pre-Ai version (multicoated) better than the AI ?