In article <8CCD59F.0007007E4C.uuout@fotobank.nl>, w.j.markerink@fotobank.nl says...
>On 23.11.96, Walter Knapp wrote about "Re: Luminars and Other Mi":
>WK>Bob Neuman wrote:
>WK>
>WK>> BTW, on your web page, you forgot the Nikkors: 19, 35, 65, and 120mm...
>WK>> I just tried the Nikkor 35mm f4.5 - very sharp (surprise! ;-)
>WK>> They are cute little lenses, if a bit awkward to use...
>WK>
>WK>Are the Nikkors using the standard microscope objective thread mounts or
>WK>some other? Do you know the max f-stops on the others?

>Bob, just to be sure: those lenses *did* have an adjustable aperture,
>right? Fixed aperture RMS (Royal Microscope Society proprietary thread,
>generally known as Royal screw....:-)) lenses are very common, and few
>camera manufacturers did *not* make those microscopes in at least one
>period of time.

At least the 35mm f4.5 Nikkor does, though non-auto, of course, darn!
I would guess that the others do, also (though the stops are marked
in numbers, not f-stops [like, "1, 2, 3", etc.]).
Hope This Helps