A few years ago, Sigma released the 14mm f/1.8 Art lens, which had the widest maximum in a full frame 14mm lens by more than a stop. Recently, they released the 14mm f/1.4 DG DN Art, which blows past the f/1.8 version by two-thirds of a stop and claims the title of the world's widest f/1.4 full frame lens. Can it offer performance and image quality to match? This excellent video review takes a look at everything you can expect.