Are there lens hoods like the one on the Leica Q for all lenses and how do you prevent them from rotating when focusing?

Hello

this is a scattered light diaphragm or Leica that is precisely adapted to the optics has 2 diaphragms for the Q. Bzw in the Leica module fit several scattered light diaphragms, but the Q has its own scattered light diaphragm thread with cover ring.

Lenses always have a stable/static front frame. Mid-rotating front frames are available only with low-cost optics, mostly with Kit Zooms