Archived posting to the Leica Users Group, 1999/08/05
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>Date: Wed, 4 Aug 1999 10:26:25 +0100 >From: "Simon Pulman-Jones" <spulmanjones@lbs.ac.uk> >Subject: [Leica] RE: actual focal length > >Bill Rosauer wrote: > >"...only Leica has the integrity to >actually engrave the actual focal length of the lens on the barrel of lenses >50 mm and longer." > >Can anybody explain how the numbers engraved on the barrel beyond the >infinity markings relate to actual focal length? I find 00 on my Noctilux, >05 on my 200/4 Telyt, and 10 on my 90 Elmarit-M. Is this variation from the >nominal focal length in hundredths of a millimetre? If so, there appears to >be no plus or minus indication. > >I can't imagine what use this information could be to me, but I'd still like >to know... > ||||||||||||||| 05 tenths of mm = 0.5 mm. For your Telyt 200 the exact focal length is : 200.5 mm. For your Elmarit 90 : 91 mm. On my Elmarit R-90 I read : 95 <:-o). So... the exact focal length is : 89.5 mm. I guess it could be important to know these data. I know that japanese manufacturers "cheat" on the focal length of the lenses. For instance my C**** 28-105 is a 30-95 according to CI. Leica does not cheat even with the "japanese" leica lenses. Dominique Pellissier