[Leica] 1,4/80 and 1,4/75

[imxputs <imxputs@knoware.nl>]

These lenses have a slightly different performance. They are from the same 
optical family tree that encompasses the 1,4/50 Summilux-M, 1,0/50 Noctilux-M, 
1,4/75 Summilux-M and 1,4/80 Summilux-R. The 1,4/75 and 1.4/80 are NOT 
identical in their optical formula. The assertion that they are identical 
(some earlier post on the LUG) is not true, but may be inspired by the fact 
that the 2,8/90 M and R versions share the same optical system. The 2,8/135 M 
and R versions also are identical in their optical parts.
My observation that the 1,4/75 at full aperture has a better performance than 
the 1,4/80 is valid and is supported by the fact that the lens prescription is 
different. The family resemblance can be seen in the fact that all four 
members exhibit low to medium-high contrast at full aperture. More recent 
Leica lenses in the 1,4 and 2,0 classes show much higher contrast at the full 
aperture setting. Ten years ago I would have given these lenses higher marks 
than today. Since the 1,4 and 2,0 ASPH family we are in a different game as 
far as full aperture performance is concerned.


Erwin