Looking first at sharpness, centrally we start off at a very good level at f/1.8 and f/2.8, rising to excellent ... For this review, the lens was tested on a Canon EOS 5DS R using Imatest.
Central sharpness is very good at f/1.8 and f/2, excellent from f/2.8 through to f/5.6, very good from f/8 to f/16 and fair at f/22. The edges are good at f/1.8 and f/2, very good from f/2.8 to f ...