Looking first at sharpness, centrally we start off at a very good level at f/1.8 and f/2.8, rising to excellent from f/4 to f/8. Sharpness is still very good at f/11 and f/16, only falling off to ...

At 17mm, central sharpness is outstanding from f/2.8 through to f/8, excellent at f/11, very good at f/16 and good at f/22. The edges are excellent at f/2.8, outstanding at f/4, excellent at f/5.6 ...