Archived posting to the Leica Users Group, 2008/01/06
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I find it hard to believe. Leitz/Leica have used special glasses for a very long time but as they know glasses and also what apochromatic lens design is they have never used the term apochromatic or APO glass. For example in G?nter Osterloh?s book Angewandte Leica-Technik there is a very thorough description of Apo-Telyt-R 1:3.4/180 mm lens, with discussion of different types of glass like anomal dispersion, calcium fluorite, lithium fluorite etc. but no mention about APO glass - the lens is "ein ausgezeichnet korrigiertes, apochromatisches system". As is well known, Osterloh worked in Leica marketing. All the best! Raimo K Personal photography homepage at: http://www.uusikaupunki.fi/~raikorho ----- Original Message ----- From: <wildlightphoto@earthlink.net> To: "Leica Users Group" <lug@leica-users.org> Sent: Saturday, January 05, 2008 8:15 PM Subject: Re: [Leica] The Tele elmarit 135 Is So A Real Pooch of a Lens > Raimo K <raimo.m.korhonen@uusikaupunki.fi> > >>Since when do they use this designation? > > Since 1984 at least if not earlier. > > Doug Herr > Sacramento > http://www.wildlightphoto.com > >> >>----- Original Message ----- >>From: <wildlightphoto@earthlink.net> >>To: "Leica Users Group" <lug@leica-users.org> >>Sent: Saturday, January 05, 2008 3:17 PM >>Subject: Re: [Leica] The Tele elmarit 135 Is So A Real Pooch of a Lens >> >> >>> Raimo K <raimo.m.korhonen@uusikaupunki.fi> wrote: >>> >>>>APO means apochromatic correction of the lens, there are no apochromatic >>>>elements. >>> >>> In Leica's case, APO is the designation they use for the extra-low >>> dispersion glass which their optical designers feel is essential to >>> designing lenses with apochromatic performance. This is like Nikon's >>> use >>> of the ED designation for their extra-low dispersion glass. Raimo is >>> correct that there are no apochromatic elements, but there is APO glass >>> which is used to design apochromatic lenses. >>> >>> >>> >>> Doug Herr >>> Sacramento >>> http://www.wildlightphoto.com >>> >>> >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >>> >> >> >> >>_______________________________________________ >>Leica Users Group. >>See http://leica-users.org/mailman/listinfo/lug for more information > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >