Archived posting to the Leica Users Group, 2007/01/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Larry, It seems to do a great job on my film R8 also. The 560 Telyt is one of my favorite lenses for bird and animal shooting. Also have used it for formula one shooting. Great lens with very sharp performance. Gene -------------- Original message from Lawrence Zeitlin <lrzeitlin@optonline.net>: -------------- > > On Jan 11, 2007, at 6:23 PM, Len wrote: > > > Thanks. I have the use of it (Telyt 560/f6.8) for the weekend along > > with a R8 body. I > > still find it hard to believe a simple 2 element lens can be that > > good. > > I have a friend, a professor of optical physics, at the University of > Rochester who insists that the sharpest long focal lenses have the > fewest elements. The Telyt lens only covers a field of 3.5 degrees on > a 35mm frame, 4.5 degrees on an M8 frame. With that narrow a field > you don't need to worry about all the aberrations that multiple > elements are required to correct. In fact, if you used a narrow band > pass filter, a single element lens would be almost ideal. Obviously > Leitz engineers agreed and the results confirm the theory. We need > the multiple element ASPH designs because we insist on short focal > length fast lenses for multicolored subjects at close ranges. > > The 42" Yerkes telescope, the biggest refractor telescope in the > world is a two element achromatic. > > Larry Z > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information