Originally posted by Wheatfield I don't think it is fair to blame the camera body though, when all it is doing is showing up technical weaknesses in other parts of the optical system.
This is dubious. My FA43 just
begs to be stopped down to at least f/2.2. But this is not so with the FA*85. One of the reasons it commands a good price is its ability to deliver acceptable sharpness even wide open.
The shot of your dog is exactly what the FA43 wide open on the K-5 will look like, based on my own experience as well. While not unbearable, the softness is apparent (By the way, this doesn't stop the FA43 from being a great lens).
If the FA43 were on the K200D or K-x, the softness wouldn't be improved much. But as we have seen, with the FA*85 or Sigma 85, it
is. That's because in the case of the 85s, even wide open, the lens isn't the limiting factor.