Archived posting to the Leica Users Group, 2008/04/21
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Apr 21, 2008, at 12:28 PM, Peter Klein wrote: > Noctilux focus shift is discussed in the Gunther Osterlach book. > Written in the 80s and recently re-released. I have a copy at home. > > Erwin Puts has actually measured it: > http://www.imx.nl/photo/lenstest/noctilux-m_11050mm.html I never saw this well written article...thanks Peter. It says a lot, but sadly there is nothing about the influence of cow poop. Steve > > > Sorry to aberrate your sphericals, but there it is. :-) > > --Peter > > Mark Rabiner sez: >> THAT'S COOL PETER! SHOW ME in the Leica literature where it says >> that when you stop down your 5 grand Noctilux 2 stops it goes out >> of focus! Have you got a URL? First three letters of the authors >> last name? > > I sez: >> Adam: It isn't a question of microlenses. Focus shift as one stops >> down is an optical property of many fast lenses, including the >> double gauss and Sonnar families. > >> Mark R: The Noctilux focus shift is well-known and even documented >> by Leica. It happened visibly even on film. It isn't stupidity, or >> even hydrogen, it's physics. A newer design could minimize the >> issue--floating elements, aspherics, etc. > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information best, Steve "I never wanted to be famous" http://www.blurb.com/bookstore/detail/186890