Archived posting to the Leica Users Group, 1999/06/28
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Lucien wrote: > Dr.Richard Clompus wrote: > > > A floating optic is usually one lens or a lens group that changes position > > (forward or backward) as the lens is focussed from distance to near. It is > > done to improve imaging performance at closer focussing distances and > > usually decreases curvature of field. This lens design is a recent addition > > to Leica lenses (perhaps in the last eight years)..... > > Richard, > > I think it's more than that. The 24/2,8 is here since 1974. > OK, it's a Minolta design. > ;-) > > Because of floating element, I don't think we will ever see > an Leica R camera with an AF system 'a la Contax AX'. > Canon has some AF lenses with Floating elements ! Thus, It should be possible for Leica to do the same ....... Xavier > > With that system you loose the quality improvement. > > Most of the Leica R wide angle lenses may suffer with that > AF system: > > 15/3,5 (1980)- 19/2,8 (1990)- 24/2,8 (1974)- 28/2,8 (1994)- > 35/1,4 (1984) > > Because with the following lenses also, the optical groups > are not moving altogether, I think there will be a problem too: > > 100/2,8 - 180/2 - 180/2,8 APO - 280/2,8 - 280/4 - 400/2,8 - > APO Module. > > Lucien - -- - ------------------------------------------------------------------------- Logean Xavier e-mail: xavier.logean@epfl.ch Swiss Federal Institute Phone : ++41 21 693 52 57 of Technology Lausanne (EPFL) Fax : ++41 21 693 66 10 Computer Science Department (DI) url : http://icawww.epfl.ch Institute for computer Communications and Applications (ICA) CH-1015 Lausanne - --------------------------------------------------------------------------