Nikkor Internal Filter Wheel

[Bill De Jager]

A few older Nikkor lenses have a filter wheel within the lens (8mm fisheye, 5cm mirror [correction: 1000mm, F version], and probably others).  Does anyone know what size these filters are?  Are they the same 39mm filters used in other Nikkor lenses, or are they any relation to the 13/15/16mm or 22/29mm filters Nikon used to produce?  I'm thinking of having some replaced and I'd like to know what size they are before I approach a shop.  Has anybody else tried to do this?

[Bjørn Rørslett]

These internal filters are quite small. Not sure every lens having these use the same size, though.

[Erik Lund]

They are lens specific as far as I can see, you would need the correct thickness,,,

Edit: The fish-eye lenses,,,

[Bill De Jager]

Thank you, Bjørn and Erik.

[Bill De Jager]

Somehow I confused the 5cm f/5 F-version with the 1000mm f/11 F-version as I was juggling both lenses along with the 1000mm AI.  All three are about the same size and superficially look similar.  The difference in focal length is offset by the difference in effective aperture.

It turns out that the one with the filter wheel is the F-version of the 1000/11, and according to Roland's site that one has 39mm filters on the filter wheel.  When I tried earlier I couldn't open up the plate to get to the filters; I finally figured out that I don't have quite the right tools.  I hope to remedy that tomorrow, although I also wonder if someone used Loctite on the screws.  The 39mm filters will make it a lot easier as I expect I can get new glass of various types placed into several spare filter rings.  That's if I can get the housing opened!

I was unable to open up the filter wheel housing on my 8mm f/2.8 but that one is lower priority.

[Roland Vink]

The 1000/11 reflex can accept 39mm filter can screw to the rear of the lens (if my information is correct). The internal filter wheel accepts 34.5mm filters: http://www.destoutz.ch/lens_1000mm_f11_111597.html

The older 50cm/5 reflex also accepts 39mm filters at the rear: http://www.destoutz.ch/lens_50cm_f5_182597.html

[Erik Lund]

Ahhh - I thought this question was for fish-eye lenses only

[Bill De Jager]

Roland, thanks for the clarification on the filter size.  My copies of the 5cm f/5 and 1000/11 AI have the 39mm filters mounted at the rear as you state.  Taking off the filter made a big difference in UV transmission for the 5cm lens, but I want to get that glass replaced with something better to preserve the optical design. 

I still need to get those access-plate screws off the 1000 F without stripping the slots.  My very small screwdrivers are too narrow to provide enough torque on the screws or else the screws have been fixed in place.  I was able to get some of the relevant screws off the fisheye, but others were obstructed and again will need special tools.  Off to go shopping...

I also need to find a place that can remount filters; I have an inquiry in to S.K. Grimes.