[davidmanze]

My Sigma 50-500mm and the Sigma 105 Macro do not differentiate themselves as regard to AF adjustment, I'm not sure as to whether it's Sigma or Pentax K5 (my DSLR) which is the problem, I just write it down on a piece of card and do my best to remember to change the settings manually when changing lenses.

 

I think it's all down to incomplete lens identity, I don't think OEMs want to make it easy for third party lens manufactures to be able to give the whole package.