Some c mount lenses has swirly bokeh. this one has it too.
strange type bokeh. not so sharp at wideopen. good for portrait I guess.
Dont expect sharpness in corners, in my experience, no c mount lenses have it. IMHO. well maybe untill someday I found different one.
It's not easy to find right focus, specially wide open. but not difficult either. you just need to practice, and you will find pleasing result,
|wideopen, Remind me of Meyer Optik Trioplan 100/2,8|
|f1,4, remind me of Biotar or Helios|