This is the civilian version of the 35mm f2 Fastax Raptar, which was made for military use on high speed Fastax 16mm movie cameras. It is the exact same lens, even with the Fastax mount, except painted black instead of grey or white (US Navy) and not marked with the exact focal length to the hundredth of a millimeter as are the Fastax lenses. While the Fastax frame is standard 16mm movie format, this lens will just cover full frame, albeit with a lot of light falloff at the edges, but using the full image circle on the diagonal, as it does, affords some very swirly bokeh and adds to the very interesting bokeh this lens creates.
