Summicron vs Summicron

[Krosya]

Hi All,
A couple of quick questions. Sorry if it was discussed some place here - maybe you cen direct me to it - I couldn't find anything.
Anyway:
1. Do all summicrons 50mm/2 have same optical design? If so - do they all have same look/fingerprint and bokeh?
2. How does 40mm cron compares to them other than wider lens? Same fingerprint , bokeh?
I mean for some reason on a 50mm cron poll people chose newest and Rigid/DR the most. I wonder why, if they are the same?

Thanks.

 

[rover]

First version collapsible, lower contrast and sharpness wide open
Second version, Rigid and DR, very sharp throughout the range, lots of snap, less contrast than modern version.
Third version from the 60s, sharp and contrasty
Fourth optical version, tabbed and current, very sharp, lots of snap, lots of contrast.

 

[Biggles]

Fourth optical version, tabbed and current, very sharp, lots of snap, lots of contrast.

I've owned that lens, and I think that's a very accurate concise description of its character.

2. How does 40mm cron compares to them other than wider lens? Same fingerprint , bokeh?

I have and use that one presently. I think its pictures resemble the modern 50mm Summicron's at a glance, and I'm honestly hard-pressed to remember which one of the two I used for some of my favorite prints, shot on the same film, without looking at my notes.

If there's a difference, I'd say the forty's bokeh is probably smoother...more gradual in transition from sharp to creamy out-of-focus. My fifty's was kind of immediate in comparison; still gorgeous, though.

No experience with any of the older Summicrae, but I understand they're of noticeably different character.