So my wife is the shutter bug and in a quest to do more things together I decided to pick up a camera. Being an advocate of open standards, open source, and industry collaboration of course I was going to get something in the micro four-thirds form factor. So a few weeks ago I grabbed an Olympus PEN EP-2 from Amazon, body only, and a kit lens. Being an engineer at heart ( and pursuing such as a career ) I also picked up an M42 lens adapter and started hunting down manual lenses. I'm the kind of guy that prefers operations to come with trim adjustment knobs, and don't like things happening automatically when I can do them myself. I drive stick. I run Linux. Naturally I'd opt for manual lenses. While the selection of preset lenses isn't bad, I'd like to use some of the auto lenses, and while using them in a stop-down mode also isn't bad I don't see why an adapter can't be made which can push the aperture pin. I went looking for one, and couldn't find it, so please stop me if they do exist. So being the hacker I am, I pulled the lens mount off my EP-2 and threw it up on the optical comparator: Subscribe to see EXIF info for this image (if available) Subscribe to see EXIF info for this image (if available) I then dropped the coordinates into a least-square fit scipy module and had it spit out the closest circle. I plugged the coordinates into FreeCAD and am now close to having a model of the camera side of the interface. Subscribe to see EXIF info for this image (if available) Next will be the M42 mount ( easy, of course ) and then comes the fun part: the aperture control mechanism. I'm a rather busy student, so don't expect this to happen tomorrow, but I'm definitely having fun with my new camera!