Fun coincidence and whats the Difference between AI and Pre-AI

Paid my Photopusher a visit yesterday and came home with a 105 f/2,5 nikkor. I thought it was an AIS or at least an AI but according to MIR and the serial number which is actually the one mentioned on MIR its a pre-AI.
Eccept for the exteriour and the f/32 minmum apperture on the pre-AI what are the differences
Best regards

You will find on the Non or pre AI lens the apperture ring is smooth completely all the way round the back edge. An AI lend will have a machined 'step' cut into the back edge, or a pre AI lens may have been converted to an AI type and will have the machined edge or even just a machined 'cut out' in place of the complete step.

That machined step on an Ai lens matches up with a piece on F3 generation and newer Nikons to indicate the f-stop of the lens. A pre-AI lens can't be mounted on these cameras unless either 1) your camera has a little button that lets you swing the tab out of the way - if so, you can mount a Pre-AI lens and use stop-down metering. or 2) Your Pre-AI has been "Ai'd " which means the original smooth F-stop ring has been replaced be a new F-Stop ring with the appropriate Ai notch cut out. Nikon used to provide Ai kits for doing this. If your lens has been Ai'd, then you can use it on any Nikon SLR.
If your lens has not been Ai'd, unfortunately, there aren't many kits left. However, there are a few people out there who will machine the cut-out in your existing f-stop ring.

Soeren said:

Paid my Photopusher a visit yesterday and came home with a 105 f/2,5 nikkor. I thought it was an AIS or at least an AI but according to MIR and the serial number which is actually the one mentioned on MIR its a pre-AI.
Eccept for the exteriour and the f/32 minmum apperture on the pre-AI what are the differences
Best regards

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The f:32 minimum aperture denotes a Gauss type version. The earlier versions were a Sonnar derivative and had f:22 as a minimum. Factory Ai lenses had a step in the rear of the aperture ring as well as an extra scale of (smaller) aperture numbers to be show the aperture in use in the viewfinder, non-Ai lenses that were modified do not have the second scale. Sonnar or Gauss, Ai or pre-Ai, it's a superb lens.

Thanks guys. Fortunately it is Ai'd and it's in superb condition. According to the serialnumber its the first with the rubberized focussing ring Im a happy man.
I read somewhere that some earlier 105mm lenses had curved appertureblades, mine hasn't
Best regards

One of the nicest lenses Nikon ever made.

Mark Crabtree said:

One of the nicest lenses Nikon ever made.

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Undoubtedly; sold my AIS a few years ago unfortunately. I've only got the 2.0/85 AIS now; another greatblens.

Can anyone explain the image quality differences between the Sonnar and the Gauss 105? Preferably with external differences as well?

MikeTime said:

Can anyone explain the image quality differences between the Sonnar and the Gauss 105? Preferably with external differences as well?

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The Sonnar stops down to f:22, the Gauss to f:32. There were several versions of each, but the minimum F stop is the one sure way to distinguish between them.
As for image quality, the one sure way to know is to get one of each and try them, they're not expensive and you can sell on the one you don't keep for what you payed or a bit more. I've had mine, a '60s Sonnar, for about 14 years and I'm still just tickled pink every time I look at the results. The Gauss version is reputed to be a bit sharper (!!) at close range.

The Mir site is a good reference for different versions of all Nikkors.

I had three copies here last year just by coincidence of some trades I'd made. Since they were on hand, I tested them for sharpness and out of focus quality, plus spent some time just shooting with the Sonnar version.

I've had the 1st Gauss version for some time, but seldom shot with it since it is not a focal length I use much. I only realized a couple years ago what a great lens this is. A Sonnar version showed up with some stuff from a friend, then a mint AI version showed up with some other stuff.

The bottom line is that they are all great. Each newer version showed some improvement in sharpness, though all were really good. The sharpness difference between the two Gauss versions was just barely distinguishable to me with a much more precise setup than I would ever use in real life.

I was already familiar with the character of my Gauss lens, so spent some time shooting with the Sonnar. In the end I kept the one I already had (early Gauss) and sold the Sonnar and AI on. I already had a friend interested in the AI, and sort of prefer the single coated look anyway. I didn't find any advantage to the Sonnar; it had a very nice look, but so do the redesigned ones. I have seen one claim that the very earliest Sonnars were the sharpest of all at infinity; I have no reason to doubt or to believe that, but the Gauss is so sharp it challenged my ability to test it. I suppose somebody might prefer one or the other for portraits, but I can't imagine being dissatisfied with any of them.

Now, it would be great if I just had some use for it. I will say that this was a very handy focal length back when I had newspaper jobs.

Mark Crabtree said:

I ... sort of prefer the single coated look anyway.

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In B&W, color, both?

lxdude said:

In B&W, color, both?

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"Sort of" was my qualifier since I don't have a very strong feeling about that aspect. I haven't done any extensive comparisons, but as a generalization don't notice liking color being any less with single coated lenses. I think that has been a common feeling from folks using the Voigtlander Nokton lenses where you have comparable lenses with different coatings.

I think the coating thing is going to come down to personal preference. And, of course, we're talking about modern (to me), coated lenses not uncoated lenses. And my use of the expression "single coated" may not be ideal either, since a lot of Nikon lenses from the late 60's and early 70's seem to have more sophisticated coatings than the very simple early coatings.

Just wondering, as I have lots of multicoated lenses- Pentax, Nikon, Fuji, Bronica- yet there's something about my one non-multicoated lens, a 200mm f/4 Super Takumar, that is just so nice in color. I've heard people state a preference for non-multicoated lenses for B&W, which I assume has to do with a sort of classic look.

Oh regarding coating. Does the pre-AI versions have a "soft" coating that will not tolerate cleaning solvents like e.g those in wet tissues for cleaning glasses?
Best regards