Sigma last year launched two wide-angle prime lenses for Sony E-mount and Leica/Panasonic/Sigma L-Mount full-frame mirrorless cameras, the Sigma 20mm F1.4 DG DN Art and the Sigma 24mm F1.4 DG DN Art. The 20mm prime is particularly noteworthy since it’s a somewhat unusual lens. Except for the Sigma 20mm F1.4 DG HSM Art for DSLR cameras, the Sigma 20mm F1.4 DG DN Art for mirrorless is the only 20mm F1.4 lens available for full-frame cameras. Nobody else makes a lens like this, including Canon, Nikon and Sony. There are 20mm F1.8 lenses but no 20mm F1.4 lenses. One of the most surprising things about this unique lens is that it retails for just $899. Read my hands-on review of the Sigma...