The KO-140М is a fast lens designed for projecting 35 mm motion pictures. The lens employs a four-lens aplant design, also known as the Petzval lens. This results in a considerable field curvature.The optical elements are covered with a single-layer chemical coating.
I use this lens on full frame Canon 5DIII for portraits. Lens don't have any focussing mechanism, so you must DIY or buy one. Lens can be sharp, but has very strong field curvature. Bokeh has tendency to swirl.
p.s. Back focal distance (from lens): is not 52.43 mm, but about ~63mm