I have a Sigma 50-500 and not yet used as I want; few shots and only 10/15% acceptable (most of my shots are too soft).
I sent the camera to Canon (10D) to be checked and it is ok.
So now my question is: would I try to buy a new Sigma100-400 SO, or in case of airplane shots the SO/IS systems are not necessary?
The lens itself is good, because sometimes I have a very sharp images, so I believe that the problem cold be solved by SO/IS system.
Please let me have Your advises.