Super-quiet and fast auto-focus (HSM) makes for a lens larger than most f/1.4s. Slightly sharper by a hair than the others—price is higher, too.
Standout Spec: Ring-type AF motor allows for manual-focus override when shooting in the AF mode.
Sigma 50mm f/1.4 EX DG HSM AF: Lens Test
Leica Summicron-M 50mm f/2
Pentax 50mm f/1.4 FA
Canon EF 50mm f/1.4 USM
Canon EF 50mm f/2.5 Macro
Sony Alpha 550