35/1.4 ASPH - Coma

["Richard W. Hemingway" <n5xrd@telepath.com>]

I must plead quilty to the post about coma in one of the ASPH lenses.  I
bought a new 3 yr passport warranty lens and shot it against the 35
summicron for a while.  I was shooting christmas tree lights in the local
mall.  They ran across the frame from side to side and in the top corners.  

Coma looks like triangle or butterfly shaped lights.  Look on page 60 of
Osterhoh's book: "Leica M, The advanced school of photography" for examples.
Stars in telescopes with spherical aberration also look the same - any
Newtonian telescope near the edges, but most noticeable with large f ratios,
ie, f/6 and larger. (I am a not very good telescope mirror making nut).

I was shocked to see the coma in the lights near the corners in the ASPH.
At that time I just sold all my Leica gear and bought into a large Nikon
system.  Since I got a good price for the lens I never sent it back to Leica
- - though I should not have sold the Leica gear and should have sent it back
to Leica.

Since I have sold all my Nikon gear and now have tow M6 bodies, 21/2.8;
35/1.4 ASPH; 75/1.4; and 135/4.0. Interestingly, it is now a year since I
tested the first ASPH and I tested the new one against the same string of
lights (as well as other light sources) and did not find any coma.

This is a non-scientific test.  Since I posted this before, someone else
mentioned that he thought the 35/1.4 ASPH lenses had some variation between
them.

Dick Hemingway
Norman, OK