A little more on the Sigma Art 20mm f1.4. Really just a review of a review. He does mention this though: "Folks from Sigma have mentioned that they have no intention of developing cinema lenses..."
http://nofilmschool.com/2015/11/sigma-20mm-f14-art-lens-sony-a7s-ii-cinema5d
http://nofilmschool.com/2015/11/sigma-20mm-f14-art-lens-sony-a7s-ii-cinema5d