If you have a nice lens that you’d like to use with a camera of a different brand, Novoflex probably has an adapter that will let you do that. With the Novoflex Adapters, you can marry up camera bodies and lenses with different bayonet mounts. No functions will be transferred; you’ll have to adjust the lens manually. Novoflex suggests using the stop-down metering/aperture priority. They also warn that physical limitations – “flange focal length difference” – mean not every camera/lens combination is possible. Prices vary depending on the combination. Novoflex seems to be a German company, but they sell internationally. Visit their dealer finder page to find one near you.