That's right, these sample images below were taken with an Olympus Pen F 38/2.8 on a GXR without the use of an adapter. All I did was hold the lens in on the body. I have used a 20mm and the result was the same. You can see that the set up focuses correctly close up and at distance; there are no masked corners and no unacceptable vignette, either wide open or stopped down. Detail is great.
In the days of film, there was no adapter to put a Pen F lens on a Leica M body. The reason is twofold:
- The Pen F is an SLR and its lenses have no RF coupling
- Pen F is a half frame format and the image circle wouldn't cover full frame
Consequently, most adapter makers wrote off the idea and I have been unable to find such an adapter in Hong Kong. Most people turn me away saying it's 'impossible'.
However I looked up the flange-focal distances of some lenses and there is no reason why it should not work.
- Leica M mount: 27.80 mm
- M39 (Leica) Screwmount: 28.80 mm
- Olympus PEN F: 28.95 mm
There is plenty of extra register; more than for LTM and that's very commonly adapted onto an M body. Furthermore, the Pen F bayonet fits comfortably within the inside radius of the bayonet protrusions of the M socket.
Having been turned down by an adapter supplier I took a few photos and showed them what I'd done. I showed them the how the lens fitted with room to spare and demonstrated the lens focusing at infinity and at close range. They are looking into it and I'll let you know if there are any developments. They already have the CAD models for LTM and Pen F and the registers, so it's more or less a matter of seeing if the side walls are thick enough and then pressing 'go' on the CNC lathe.