I wonder why they decided to make it so dark... f/17.48 is really really dark. Actually reading Wikipedia numbers it seems even darker at f/18.91. The focal len

I wonder why they decided to make it so dark... f/17.48 is really really dark. Actually reading Wikipedia numbers it seems even darker at f/18.91. The focal length is impressive at 3/4 km, so probably they wanted to privilege the angular resolution going toward the diffraction limit.