Design of 35/2 versus 35/1.4

[KEVIN BURKE <KBURKE@iterated.com>]

>From: Charles E. Love, Jr.

>[...]  The old
>(non-asph) 35 1.4 is not as good as the f2--a very old design.

I'm not much of a historian, but from what I know of the current 35/2
and 35/1.4, they share a similar cross-section/geometry and belong
to a similar general classification of lens design type.  Both have 7
elements in 5 groups and are modified Gauss types.  If memory serves,
the individual element types (positive meniscus, negative biconcave, etc.)
and the glued surface positions are the same.  I don't have data
on the glasses used or radius of curvature for each element suface, but
figure that this is where the biggest differences might be.  Also the 
diameters
are different (obviously).

I'm probably going to get the dates wrong but I think the 35/1.4 Summilux
was introduced in the early sixties (?) and the current 35/2 Summicron
was available 1979 or 1980.  Its interesting that the "newer" design shares
so much with the old war horse.

 -Kevin
kburke@iterated.com