Yes, the screw thread is a bit more complicated than a bayonet connection. All, which the 20 seconds compared to bayonet connection are more too long, is not the aperture. I enjoy it, make do with only 2 stops for all lenses and this collapsed in case of need to have always with you. The rubber quality is very good, thus ensuring the durability. In zoom lenses in the wide angle simply pushed back and activated at normal focal length with a short handle again.
