Did you check the short end? Wouldn't be interesting if it was just another 28-80? BTW, nominal and actual focal lengths have always been somewhat problematic, but 10+% is a bit out of line.
Ciao, Graywolf http://pages.prodigy.net/graywolfphoto ----- Original Message ----- From: "keller.schaefer" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, July 03, 2003 9:29 AM Subject: FA 24-90 focal length > Some weeks ago I inquired here about the FA 24-90 lens quality. Subsequently I > bought the lens and shot some film with it. I would rate the optical quality as > very reasonable and the mechanical quality as not-so-good. > > What puzzled me was the fact that when looking through the viewfinder the lens > in the longest '90' mm position still had a shorter (!) focal lenth than my M > 2,0/85. I tried to verify this by mounting the remnants of an old ME Super > K-mount to the lens standard of a view camera and attaching the lens to it. As > the difference in distance between lens and film (when moving the lens from > infinity to 1:1 magnification) equals the focal length, I was able to measure > this with some precision. > > The longest focal length turned out to be 81 mm (I'd say plus or minus 1 mm). > > I have also tested some other Pentax lenses: > M 2,0/35: 34,8 mm > M 1,4/50: 49,2 mm > M 2,0/85: 83,9 mm > M 2,8-4/40-80 at 80 mm: 78,9 mm > and found these are quite close to what the lens designation says. > > Pentax Germany did not dispute my measurements but admitted that the 90 mm > designation is an exaggeration for competitive reasons (...everybody does it > like that). > > So, effectively, this lens is an 24-80. > > I thought you might be interested. > > Sven >
