Page 49 of the OM-D EM-5 manual reports that non-micro 4/3 lenses require choosing a focal length when engaging one of the image stabilizer options other than off. Yet, when I mount a lens such as Olympus' new 75-300mm II lens, the focal length is reported at 50mm. It's the same with mounting any other Micro 4/3 lens that I have. The 50mm focal length seen is probably be a factory setting because it was something I had not noticed or monkeyed with before. I'd imagine that it would be a nicer interface if the focal length setting was grayed-out if a micro 4/3 lens was mounted; and enabled when a non-micro 4/3 lens was mounted.