Archived posting to the Leica Users Group, 2008/04/21
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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 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.