Your adapter is setting the mount register too deep. I had the same thing happen with a Pentax M42 adapter. I bought a different one, which allows focus slightly beyond infinity. Cost me $6 for the replacement.
Most lens mount adapters for FourThirds and Micro-FourThirds intentionally run about half a millimeter short in order to ensure infinity focus with all lenses of that mount. This throws off the infinity focus point by a couple of degrees but is much less difficult to work with than adapters that are slightly too long, preventing proper infinity focus. On Tue, Mar 15, 2011 at 3:02 PM, Dario Bonazza <dario.bona...@virgilio.it> wrote: > Hello gang, > > I've just tried a few Pentax lenses on my Panny GF-1 (via K-micro4/3 > adapter), just to find a weird behaviour. > > With close subjects (inches to meters), the actual distance of my subject > (properly focused by looking at magnified LCD) can be similar to that one > indicated on the distance scale of the lens. However, when trying to > properly focus at infinity I have to set a much closer distance on the lens > ring, with larger and larger offsets as focal legths shorten. > > Examples: > 100mm lens focused at infinity -> focusing ring is set at 15-20m; > 50mm lens focused at infinity -> focusing ring is set at 7-10m; > 28mm lens focused at infinity -> focusing ring is set at 3m! > > With a Samyang 8mm fisheye, there's no way to focus (lens helicoid has no > run enough to find focus). It happens that by setting the focus at its > minimum focus distance, the lens is almost (but not yet) focused at > infinity. By approaching the subject, things become worse. > > Have you ever seen anything like that? How would you explain that? Wrong > adapter? Too short to set proper register distance for K-bayonet lenses? > > Cheers, > > Dario > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. > -- Godfrey godfreydigiorgi.posterous.com -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.