The DSB range of the Yashica brand is not supposed to be that good. It was their lowcost alternative and single coated. But this Yashica DSB 50mm/1.9 has surprised me a lot. I love the ML 50mm/2, but it would be hard to compare these two. The DSB is a little bigger which makes it easier to handle the rings.
Flowers with Yashica DSB 50mm/1.9
I will soon post some more on the yashicaforum.