So I've got some of the lenses that have been discussed and I noticed something; the F 50 1.7 and M 50 1.4 seem to be the same height. So I did this little sloppy test;
I wanted to compare the lenses about how they would actually be installed on whatever camera I'm using. So for the M 40 on the left, it has the DA 40 Ltd hood installed with a film can cap installed. Then the F 50 1.7 with the thin caps that have been on FA and DA lenses. Finally the M 50 1.4. I'd probably use a UV filter on the 50's, honestly, but this is still a valid comparison as the "winner" would get the same filter, making it a wash.
From what I can tell using just eyesight, the F 50 1.7 is at most a single millimeter shorter than the M 50 1.4. All lenses are at their shortest via focusing them to infinity.
Is the M 50 1.7 any shorter than either the F 50 1.7 or the M 50 1.4?
p.s. great work on that F series focus ring, Pentax, really nice work there, it's almost usable.
p.s.s. I'm not buying an A 50 1.7 when M 50 1.7's are cheaper and more sturdy and good lord people I've already stated this.