[Leica] Leica performance stopped down/shooting Leica wide open

["Anderson, Ferrel E" <AndersonF@ria.army.mil>]

I shoot with Leica R lenses since almost all of my work is for scientific
applications.  I have shot at maximum aperture with my full Leica R lens arsenal
less than ten times!  (This was before I got the 400mm f/6.8 Telyt which I shoot
wide open 90% of the time)   However, I once found myself shooting a bear effigy
Indian mound located high above the Mississippi River at Wyalusing State Park,
Wisconsin, at sunset.  The light was dim, but it was low though, and was perfect
in revealing the contours of the low mound against the surrounding terrain.  I
shot it with my 50mm Summicron-R (the first version) at f/2 at 1/15 second on
Kodachrome II film.    I braced the camera against a tree.  The shot is very
successful, and displays excellent sharpness and a central glow that is very
attractive.  The picture looks as though the center of the scene is accentuated.
One of my best mound pictures.  Since then I tested this lens at f/2 by taking a
picture of a general scene with lots of clear sky.  Talk about vignetting!  It
is very discernable, and doesn't come under control until about f/3.5.  My point
is that stopping down improves the performance of this lens remarkable in terms
of controlling vigneting, but that in certain conditions, such as I describe
above, the vignetting is just what the doctor ordered!  Since then I have
acquired the most recent 50mm Summicron-R lens, and have found that it has much
improved performance at f/2 in terms of vignetting, and also that it has much
better field flatness for close-ups of flat subjects.  The first Summicron is a
beautiful lens though.

Ferrel Anderson
Davenport, Iowa