There are many great lenses in the Panasonic Lumix G catalog, but none so prestigious as the six produced in partnership with Leica. The Panasonic Leica DG Summilux 12mm f/1.4 ASPH, hereafter known just as the 12mm f/1.4 to simplify things, is the latest addition to the Leica series, and claims the title of the widest and brightest autofocus rectilinear lens for Micro Four Thirds.