Switzerland used to make luxury reflex cameras. The brand used to make cameras in the French-speaking part of Switzerland near lake Geneva until it sold for large format camera manufacturing in the German-speaking part of the country.
Made for Alpa 35mm cameras from 1958 to 1968, the Kern manufacture developed a legendary piece of optics and mechanics. The Kern Macro Switar lens sharpness is legendary, and the bokeh much different than other similar lenses. What also makes this lens unique is the long focusing-ring throw. You will need two and three quarter turns from the minimum focus (1.8x magnification) to infinity. It is, however, very precise, and once gotten used to, feels pretty awesome.
The depth-of-field linked aperture reflects through a smart system of holes on the lens barrel. The rendering of this vintage lens is unique, with high definition but some light scattering and very particular bokeh. There is also a contemporary Kern Macro Switar Alpa 50mm f1.9 that adds coatings and performs better regarding both light scattering and definition, and I will try to find one to test soon.
While I expected to be underwhelmed by the lens, and at first a bit surprised by the old-school feel of the captures and bokeh, the lens has tons of character and will hardly look like anything else.
Here are a few examples of this rare lens.
You can always check some other photographic examples on my Instagram page.