Nikon Nikkor 65mm SW, f:4 - Sharpness

[Madsen]

I have a example of this lens which is excelent, but beware of the

image circle at f 4.0.

I usualy uses the lens at F. 11.0 and 16.0, where it is a excelent

very sharp lens

[Steve Daniels]

I have the Nikon SW 65 f4 and find it to be extremely sharp. Even wide open, the ground glass image is very sharp in the center. I do not stop this lens down past f16 because of diffraction. I do some very long exposures and use ND filters to accomplish them rather than stopping down past f16. By f16 everything should be sharp with this lens.

You might check to see that the rear element is seated properly. I have seen a few lenses that were optimized for close up (not wide angle, though), and a spacer was inserted either behind the front element or in front of the rear element. It would look like a thin brass washer. If there is one there, remove it and it should improve sharpness.

In some cases, a thick lens board can cause the rear element to not screw in all the way.

If none of these are the case, you may have a defective lens.

Steve Daniels
St. Petersburg, FL

[Michael S. Briggs]

Nikkor-SW lenses come from the factory with a thin brass shim in between the front element and the shutter. This washer is supposed to be there for the intended use of the lens. It wasn't added by some photographer to improve the lens for closeups. I would be surprised if removing the brass shim from a Nikkor-SW improved the performance for distant subjects. Apparently the spacing of the lens cells on lenses of this design type is critical and the manufacturers compensate for manufacturing variations by tuning each lens with a shim.

[Steve Daniels]

Note that I mentioned that I had not seen it done on wide angle lenses. I have never taken the front elements off of my 2 Nikon SW lenses, so I have never seen them, and are probably there.

In the seventies and before that, shimming was done a lot to increase performance for close up photography. I once had a Rodenstock 180mm that had shims (4 of them) in the box and instructions on how to use them for this purpose. I haven't seen it done much since that, probably because of more modern techniques in optical performance.

Is it possible that the shims needed for Juergen's lens are missing? If the lens is a used one, it's very possible.