Central sharpness is very good at f/1.4, excellent from f/2 to f/8 and very good at f/11 and f/16. The edges are also very good at f/1.4, excellent from f/2 to f/8 and very good at f/11 and f/16.

This lens from Sigma ... 1 and the lens at 320mm. Click on each comparision photo below to view full size versions 50-500mm set at 50mm and f/8 50-500mm set at 500mm and f/8 50-500mm set at 50mm ...