Focusing is not as smooth as with my Zuiko lenses, but it is not stiff. Just fine.
But on that particular day (when shooting the above scenery), I had a slight problem with my other Samyang lens, the 14mm f/2.8. The tiny ring above the aperture ring eith the white marker for the set aperture got lose. A tiny screw went lose. Fortunately I had the right tool in my photo bag to fix it.
