Sigma 19mm F2.8 DN A MFT mount review: Modest price, modest performance?

Introduction With an APS-C image circle, Sigma’s DN series is specifically designed for mirrorless models from Sony and the smaller MFT format adopted by both Panasonic and Olympus. Originally launched as EX types with f2.8 apertures, the firm has refreshed the original two focal lengths (a wide and standard) designating them as their prestigious Art series and added a third, a 60mm short telephoto (reviewed previously).As the wide-angle of the three, this 19mm A series lens is an upgrade of the earlier EX model of the same focal length and, with an MFT mount, is the