The Sigma 18-50mmf/2.8 EX DC Macro is a wide to normal angle, zoom lens made by the SigmaCorporation. The lens is produced in Canon EF mount, Four Thirds
Sigma50mmf/1.4 EX DG HSM is a normal prime lens made by the SigmaCorporation. The lens is produced in Canon EF mount, Four Thirds System, Nikon F-mount