Questions about adapting an Olympus Pen EED lens to a Pen FT

[r_a_feldman]

I’m thinking of trying to adapt the 32mm f1.7 lens from an Olympus Pen EED to an Olympus Pen FT as I like the idea of having a ~45mm pancake lens on the FT, but I would like a sanity check before buying a “For Parts” EED from Japan (with shipping more than the cost of the EED) and proceeding.

There is a good series of videos on YouTube showing how to disassemble an EED, so I have a pretty good idea of how the lens works and how to remove it from the body. I am aware that the lens has a combined shutter/diaphragm, but that should not be a problem. I also have a Pen FT lens mount from an extension tube.

What I am unsure of are (1) the “flange to film” distance for the EED — can I get it to focus to infinity when on the FT, which has a flange-to-film distance of 28.95mm; and (2) will the rear of the lens clear the mirror in the FT — how far behind the mounting plane does the lens extend.

Comments and suggestions are welcome.

Bob

 

[Bronson Dugnutt]

I can't comment on that particular combination, but I can say that there isn't enough mirror clearance to use the f=3cm 1:2.8 D.Zuiko from a Pen S on an FV at infinity. For that lens, infinity focus is achieved when the center of the lens (not front or rear element) is 30mm from the film plane. That leaves ~1cm of the rear element protruding into the mirror box to about 20mm from the film plane but needs a clearance of 29mm.

Options in this case would be to settle for a portrait/macro setup or find a suitable myopia diopter for use at infinity.

Good luck!

Edit: the lens in question, for reference. It's still useful in DIY 'pinhole' builds and as a inspection loupe.



Edit2: Here's a useful calculator for anyone with a rig that has a furthest-focus of less than infinity. Enter the furthest focus you're able to achieve with a given setup into the 'Edge of Blur' field and it will produce the negative diopter value required to correct for infinity. https://endmyopia.org/focal-calculator/calc.html

Such lens are available over-the-counter in the US these days and can be cut into more suitable shapes & sizes.

 

[wiltw]

How do you remove a lens which is integral to the Pen EED rangefinder body, put it onto the Pen FT mount, and connect linkages for auto diaphram stop down, f/stop control, and focus?!

 

[r_a_feldman]

How do you remove a lens which is integral to the Pen EED rangefinder body, put it onto the Pen FT mount, and connect linkages for auto diaphram stop down, f/stop control, and focus?!

1. The EED is zone focusing, not rangefinder.
2. I would use manual diaphragm control, not auto. I do that now with OM1 and Nikon lenses with suitable adapters on the Pen FT.
3. f/Stop control is by the ring on the lens, which was used for adjusting the f/stop when using flash.
4. Focus is manual on the EED — the lens has a helicoid.

 

[r_a_feldman]

I can't comment on that particular combination, but I can say that there isn't enough mirror clearance to use the f=3cm 1:2.8 D.Zuiko from a Pen S on an FV at infinity. For that lens, infinity focus is achieved when the center of the lens (not front or rear element) is 30mm from the film plane. That leaves ~1cm of the rear element protruding into the mirror box to about 20mm from the film plane but needs a clearance of 29mm.

Options in this case would be to settle for a portrait/macro setup or find a suitable myopia diopter for use at infinity.

Good luck!

The standard Pen FT lens protrudes about 5mm behind the flange, so the minimum rear-of-lens-distance is about 24mm, which still could be a problem for the 32mm f/1.7 on the EED.