We're working towards our full review of the Sigma BF, the first installment of which explains how it works and what it's ...

If it is sharpness we seek, then this is our lens. Centrally, sharpness is excellent from f/1.4 right through to f/11, and still very good at f/16. The edges are exactly the same, excellent from f ...

Sharpness leaves nothing to be desired. Centrally, it is excellent from f/2 to f/4, outstanding at f/5.6 and f/8, excellent at f/11 and f/16 and still very good at f/22. The edges are very good at ...