The adapter ring is screwed onto the lens quickly. But then you go to the putting on the actual aperture. Keys - total euphemism - Press Fit visor, choke, crack, rums, at least one of the small retaining tabs is now behind the adapter ring. So from the beginning, press buttons, choke, crack, are exempt under aperture, press again to point one, buttons, ... In addition, one should remember that solve the aperture and vice versa draufklicken again one has the lens removal - a vicious circle. Truly an example of unnecessary, crazier and practice further engineering.
