Aha.
Rolleiflex...
"They never saw me clicking away. For the kind of photography I do, one has to be very unobtrusive and to blend in with the crowd."
Try that with the chimping crowd nowadays.
That can explain why I've heard f/8 is the sweet spot in general, but it really does matter with lens focal length/sensor(film) size, etc. etc. distance to subject... plus the lens itself!