Archived posting to the Leica Users Group, 2012/03/28
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]To do a wide angle fast lens, you will need retrofocus design, even for rangefinder where there's no mirror box. The mostly symmetrical designs like the Biogon do not scale to fast aperture. If I understand it correctly, a retrofocus would be like putting a reducer at the back of a longer than wide angle lens, thus adding complexity. And since fast lens make the aberration situation worse, further complex design is needed to control them. So it's sort of like a double whammy. In that sense, while the Summilux 21 is huge by Leica M standard, it's still a svelte lens for what it does. On Wed, Mar 28, 2012 at 12:10 PM, Adam Bridge <abridge at mac.com> wrote: > Just curious. Since we were talking about the Nokton lenses. > > I have a Noctilux f1.0 50mm and a CV 35mm f1.2 > > But as you head toward 28mm or 24mm it's f3+. > > As focal length increases above 50mm there aren't many fast lenses either. > > So, why the sweet spot between 35 and 50mm? > > I'm sure there are optical wizards who can explain this. > > Thanks! > > Adam > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information > -- // richard <http://www.richardmanphoto.com>