Zeiss even list the true focal length in their data sheets - the Planar 1.4/50 is 51.8 mm focal length!
When I received my 24-90 I noticed that the long end was actually shorter than my M 2/85. In the 'communication' I then had with Pentax Europe about this, they admitted (regretted) that the lens designation could be way off (with the exception of the Limited lenses where they said it would be correct). Sven Zitat von Raimo K <[EMAIL PROTECTED]>: > 85 mm lenses are not really 85 mm - there�s 5 % tolerance. Pentax could have > named it 85 but they decided to use the true focal length instead. The 31 mm > could be the same. > Some Leica M lenses have small numbers engraved on the lens barrel and they > tell what the actual focal length is - e.g. my 50 mm Summicron is really a > 52 mm. > All the best! > Raimo K > Personal photography homepage at: > http://www.uusikaupunki.fi/~raikorho > > > ----- Original Message ----- > > > Boy, that 85 sticks out like a sore thumb, doesn't it! I wonder if the > > 77ltd was aiming at 80mm but ended up 77. I'll bet the 31 was essentially > > aiming at 30 or 28. Leica made an 80 IIRC, so it's not unheard of. > <snip> > > > > DJE > > > >
