Archived posting to the Leica Users Group, 1999/12/06
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Dan States wrote: >>> I notice that the smallest focal length that bears the APO title is the 70-180 zoom. It there are reason why wide angle and standard lenses are not corrected to this degree? Is is more difficult to create an APO 50 than an APO 90? Would the benefits be the same for the smaller focal lengths in terms of real world performance? <<< It's less an issue of difficulty, and more one of need. Chromatic abberations, both lateral and longitudinal, are a bigger problem the longer the lens is. Doug Herr Sacramento http://ourworld.compuserve.com/homepages/telyt