Earliest Nikkors won't mount on my Kenko tubes

<p>I can't get my earliest Nikkor lenses (a 5.8cm f1.4 and 2.8cm f3.5) lenses to mount on my modern Kenko tubes. They are both John White ai'd and both mount to my D610 and PK-13 without a problem. Other lenses from the mid to late 1960's - a 105mm f2.5, 135 f2.8, and 200mm f4 (the first two are chopped while the last one is a full Nikon ai conversion) mount just fine on everything. </p>

<p>I'm guessing that the protruding baffle on the back of the two offending lenses is hitting against something in the tubes, but I can't figure out what. </p>

<p>Anyone have any experience with a similar issue or a possible way to fix it (other than buying some different tubes)? Thanks!</p>

 

<p>*Some* very old lenses and accessories doesn`t mount on my newer stuff and viceversa, but they are not converted. Looks like the tolerances and/or rigidity of the materials or construction is not the same (all Nikon original). But I think it is not your problem.<br /> I tend to think that yours is a simple obstruction problem. A bit of plasticine will help to locate the culprit (well, just to check the contact point, don't spread the material all inside the lens!) :D</p>

Both lenses would probably benefit from being

reversed when used for macro. So I'd suggest

getting a BR-2a or similar reversing ring. That

should solve the problem. Although it then leaves

you with only manual aperture and no fine

focus control.

<p>Just a follow-up: I picked up some old manual focus Vivitar AI tubes and all of the lenses fit fine. The whole set (12mm, 20mm, 36mm) cost $12.</p>