>>3359703S as in the new Z-mount lens line.
>>3359720The 50 f/1.8S has more elements (12 in 9 groups) than the Milvus 50 f/1.4 (10 in 8 groups).
The Sigma 50 f/1.4 Art 13 in 9 groups and the Otus 55 f/1.4 has 12 in 10 groups.
By comparison, a Canon 50 f/1.8 has 6 in 5 groups and the Nikon 50 f/1.8G has 7 in 6 groups.