[Leica] 35/f2 Summicron - Genesis to Judgement Day

[Randy Holst <rholst@micron.net>]

Hello all,

I've been (somewhat) trying to follow the discussion on the Aspheric
lenses, which has led me into another question.  While attempting to
familiarize myself with the evolution of the Leitz 35/f2 lens (for a
future purchase), I've found that:

In the beginning, there was the 8 element Summicron 35/f2 and it was
good.  Then came the 6 element Summicron 35/f2, which was purported to
be gooder.  That then beget the 7 element Summicron-M 35/f2, which had
to be even 'M'ore gooder.  Finally came the prodigiously priced
Summicron 35/f2 Aspherical, which has got to be Immaculate in
Conception.  This lens has gone through more versions than Nikon's
equivalent 35/f2 for their SLR's.

Can anyone explain to me what these improvements actually mean in terms
of sharpness, color, contrast, distortion, etc.?  Under what conditions
would I notice a difference between the first and last versions?

Randy Holst
Boise, Idaho