Showcase Yashica 28mm f/2.8 ML, CY mount

Hi there.
I want to describe here my shooting experience with CY Yashica 28mm f/2.8 ML lens. It is really well build and looks very sexy , so it's really difficult to resist temtation to posses it  . Many Internet sources suggest that optical quality of the lens is almost on par with more expensive CY Zeiss Distagon 28mm f/2.8 but I've found it does not provide any similar to Zeiss Distagon performance on m4/3 cameras at all. Starts from F5.6 it is quite nice but at F2.8 and even F4.0 it is too soft to be a general purpose lens (56mm on double-cropped sensor). Anyway it still has its own charm. Contarst and colour rendering is very appealing indeed. So I could not part with the glass so far  .
Some examples below. Camera E-M5.

F5.6

E-M5    ---       f/1.0    1/4000s    ISO 1000

F5.6

E-M5    ---       f/1.0    1/800s    ISO 200

F5.6

E-M5    ---       f/1.0    1/640s    ISO 200

F5.6

E-M5    ---       f/1.0    1/20s    ISO 200

F4.0

E-M5    ---       f/1.0    1/500s    ISO 200

F5.6

E-M5    ---       f/1.0    1/200s    ISO 200

F5.6

E-M5    ---       f/1.0    1/1600s    ISO 200

But at F2.8 it suffers from softness and kind of immage degradation too much, so I preffered to convert it BW to still like it  

E-M5    ---    0mm    f/1.0    1/50s    ISO 640

E-M5    ---    0mm    f/1.0    1/50s    ISO 640

E-M5    ---    0mm    f/1.0    1/40s    ISO 640