Re: ASPH vs. ASPH, etc.

[Pascal <cyberdog@ibm.net>]

At 17:38 -0400 11-07-1997, David W. Almy wrote:

>Erwin, a respectful request reiterated here -- can you compare the
>optical performance of the 35 1.4 ASPH to the new 35 2.0 ASPH?
>
>>From 2.0 to 16, which is better?
>
>Enquiring minds really want to know.
>

>David W. Almy


There is an extensive article on the new Summicron-M 35mm f/2.0 ASPH in
Leica Fotografie International (nr. 5/97). I got the German edition a week
ago. The article is written by S=F6nke Peters, product manager in Solms for
the Leica-M system.

It also contains a brief comparison with the Summilux-M 35 mm f/1.4 ASPH.
Here are the main remarks (translated from German):

1=B0 the construction of both lenses is similar, e.g. the front and back len=
s
elements that are inwardly curved (in total 7 elements for the Summicron, 9
elements for the Summilux).
2=B0 Contrast is on the same high level for both lenses at full aperture (of
course, the Summilux already obtains this result at its maximum aperture of
1.4, the Summicron at 2.0).
3=B0 Contrast is slightly higher for the Summilux than for the Summicron whe=
n
stopped down at 2.0 (the maximum aperture of the Summicron).
4=B0 Light fall-off ("Vignettierung") at maximum aperture could be
considerably enhanced for the new Summicron, coppared with its predecessor,
and can be compared with the Summilux at f/2.0. There is no more artificial
light fall-off when stopped down to f/4.0.
5=B0 The high optical performance of the new Summicron stays at the same
level when used at the minimum focussing distance of 70 cm.

Hope this helps.

Pascal
Belgium


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