Archived posting to the Leica Users Group, 1998/05/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>> The 400/6.8 on a VisoIII was always a real delight for me as far as >> handling went. I shot birds in flight at 20 feet, which you could't do with >> anything else (except may a Novoflex) before autofocus. Unfortunately, the >> field curvature in my lens actually changed with time (and the lens got >> less sharp), so I got rid of it in the mid 70's. > >Anyone know how this could happen? "field curvature in my lens actually >changed with time" The explanation given to me was that some glasses (glass being a fluid) can indeed flow enough in a normal span of years to cause this. Leica has used a number of exotic glasses, and I was told that this might have been the cause. Separation of the two elements had not taken place. One other person has related the same thing (re: a 400/6.8) to me. * Henning J. Wulff /|\ Wulff Photography & Design /###\ mailto:henningw@archiphoto.com |[ ]| http://www.archiphoto.com