Opticallimits

Hi Zoners, I need your advices on this:

I purchased used Sigma 150mm f2.8, tried it on arrival and it can't open more than 3.0... Sometimes 3.3. Otherwise everything else works. Is this easy fix? Should I keep it? Or more surprises might come?

Two threads for one theme?

See my answer in the other thread.

http://forum.photozone.de/index.php?/top...e-reading/

 

Eventually, terminate this thread, rather than

discussing the theme in two threads.