Sigma 40mm f/1.4 DG HSM ArtDesigned within the rigorous tolerances of a cine lens, the Sigma 40mm f 1. 4 DG HSM Art Lens is a wide normal length lens characterized by a bright design and sophisticated optical layout. The fast f 1. 4 maximum aperture helps to achieve shallow depth of field and selective focus effects, and also suits working in difficult lighting conditions. The optical design incorporates a series of low dispersion and aspherical elements, which help to improve