I’m enchanted with the rendering of this lens, which has a bokeh at least as “etched” as the Leotax Leonon 50mm f2. This lens was manufactured in-house (I understand) by the Okaya Optical Works Company, Ltd, and mounted on their Lord 5D rangefinder camera, an interesting and well made machine from the 1950s with a number of innovations, as well as this fast semi-wide lens. I am pretty sure this is a double gauss design, though I have not seen an optical diagram. The lens can be removed from the camera easily (by unscrewing the retaining ring at the rear) and is relatively easy to adapt to a mirrorless camera. Despite being quite wide and rather fast, it does not vignette severely on full frame and is surprisingly sharp and contrasty.
