Professionally adapted to Sony E Mount: Schneider-Kreuznach Radionar 80mm f2.9 Macro Cooke Triplet lens.  Adaptation has been calibrated so that you can use the original floating front element focusing mechanism, or the macro helicoid.  Either will achieve and stop correctly at infinity focus.  You can also use the macro helicoid for focusing first, then use the front focusing for adjusting soap bubble bokeh in the background.  All adaption parts are machined steel and aluminum designed for this purpose.  This is a custon design only from vyoufinder, as seen on youTube: Franka Solida III Camera w/ Schneider Kreuznach Radionar 80mm f2.9 lens: Features & Changes