Archived posting to the Leica Users Group, 1998/03/31
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Marc, I've looked at cross sections of Canon RF 50mm lenses. Only the 50/1.5 (a lens with a bad reputation) looks like a Sonnar. Their good lenses (50/1.4, 50/1.8) look like typical Gauss designs. Marco - ---Marc James Small <msmall@roanoke.infi.net> wrote: > > At 11:24 AM 3/30/98 -0800, Adam wrote: > >Roger Hicks in his book "A History of the 35mm Still Camera" Focal Press > 1984 > >ISBN 0-240-51233-2 > > > >In his brief blurb on the Sonnars: > >"It was left to Zeiss to introduce a really fast triplet derivative. They > did > >this in 1932 with the f/2 and f/1.5 Sonnars. The f/2 has a single front > glass, a > >triplet centre, and a doublet rear, and the f/1.5 has a triplet rear. > Because > >they are still essentially triplets, with only six glass-air surfaces, > they are > >still adequately contrasty, but they pay for their simplicity in other > ways. The > >f/2 is a good deal more than acceptable, and by f/5.6 or f/8 the initially > >rather poor edge definition sharpens up considerably. The f/1.5, on the > other > >hand, is sharp enough centrally but never really pulls in the edges" > > > >There was an article in LHSA Viewfinder a while back (forget by who) on > another > >Sonnnar clone, the 50/1.4 Nikkor, in which the author describes the same > problem > >at the edges, even stopped well down. > > > >Has this been your experience with the Sonnar and Jupiter? > > No. Roger and I have FAXed each other on this and related points. That is > his experience; it isn't mine, nor, for that matter, is it consistent with > Kingslake's analysis of the design. The 1.4/50 Nikkor is, of course, more > than a "clone": it is an outright theft of the Zeiss design, used > unlawfully but with the permission of the Allied occupation authorities > which was supposed to make it "all right". Of course, it does no such > thing, morally: a theft is a theft, and a thief is a thief. Canon and > Nikon built their reputations on larcened goods. > > Marc > > > msmall@roanoke.infi.net FAX: +540/343-7315 > Cha robh bas fir gun ghras fir! > > _________________________________________________________ DO YOU YAHOO!? Get your free @yahoo.com address at http://mail.yahoo.com