so I found an adapter for this nifty little lens to mount on Oly EPL5. How the heck does it focus? is the focus ring supposed to turn, or just the aperture settings? If I set to, say, wide open, the only way I seem to be able to focus is with my feet. Is my focus ring stuck, or does it not turn? Any particular tricks to using this lens on MFT cameras? I also have a 90mm super vemar. Focus ring works fine on that. thx for any ideas!