A quick check with the Chinese social network Weibo shows that the next Sigma product announcement will be for a new Sigma 50mm f/1.2 DG DN | Art lens for Sony E and Leica L mount. The new lens will have 13 aperture blades, 77mm filter size, and should be priced under the current Sony FE 50mm f/1.2 GM.
Sigma to announce a new 50mm f/1.2 DG DN | Art lens for Sony E and Leica L mount
