How to make an Olympus Pen F/FT/FV to Nikon lens adapter
by Anonymous

Having an Olympus Pen F/FT/FV camera is fun, but there are a limited number of lenses that were made and the availability of quality used lenses is not very high. My other 35mm SLR is a Nikon and I have quite a few lenses for it. I tried to find an Olympus factory Pen to Nikon lens adapter, but if you can find one the cost is very high. So I resigned myself to using the more readily available T-mount adapters that were made for the Pen F series (Vivitar, Accura and Tamron were some of the after market manufacturers of these adapters).

I ordered an adapter from an internet camera shop that specializes in used and classic camera equipment. The cost was quite reasonable. The draw back with a T-mount adapter is that the mount is essentially dedicated to one lens. When I received the adapter, I noticed that the mount was quite large. So I looked into modifying it to fit my Nikon lenses. A Nikon BR3 lens-reversing mount would work well as a lens mount for the Nikon lenses and there appeared to be plenty of room to slide the BR3 over the T-mount barrel (after the serrated edge was removed).

The Nikon film plane to lens flange distance is 46.50mm. The Olympus Pen F cameras have a film plane to lens flange distance of 28.95mm. This means that the adapter will have to have an Olympus flange to Nikon flange distance of 17.55mm ( Nikon lens-flange distance of 46.50mm - Olympus Pen F/FT/FV lens-flange distance of 28.95mm = 17.50mm adapter flange-to-flange distance).

The height of the T-mount adapter is 26.00mm from flange face to top of the serrations and the lens-mounting bracket on the Nikon BR3 is 3.65mm thick (this is the lens mount and lens release tab held onto the BR3 barrel by four screws). So the T-mount adapter will need to be shortened by 12.10mm (present height of 26.00mm - final height of 17.55 + Nikon BR3 mounting plate of 3.65mm = 12.10mm).

The outer diameter of the T-mount adapter is 49.96mm and the inner diameter of the Nikon BR3 is 49.48mm. So I enlarged the Nikon BR3 inner diameter by 0.48mm (49.96mm - 49.48m = 0.48mm). Also, the T-mount adapter release button area needs to be opened up on the Nikon BR3. This is what you end up with after machining the T-mount adapter, the cut off serrations and the remaining serrations turned down to the diameter of the T-mount barrel, and the machined BR3 with the notch for the T-mount adapter release button and the 3 set screws to hold the pieces together.

The last step was to fit the pieces together and make sure that the Nikon lenses would focus at infinity. A little light filing was required in order to get an exact final flange-to-flange distance of 17.55mm. The finished adapter works very well and does focus to infinity. Total time was about 3 hours.

This modification to a T-mount adapter could be done for the following camera lens mounts: