picture credit dr. Milos Mladek, 2004
The Sphearogon family is basically a series of prototypes, embracing a series of different focal lenghts and evolving in the pre-war era 1935-1936. They were aimed yo aerial pgotography and survey. A 180° and more capable lens could be used in ground photography even flying under the radars. Very few arrived to our days.
This one is 16mm f6.3 prototype is said to cover over 200°.
A very special thank goes to my friend Marco Cavina for all the knowledge he shared with me about these early lenses.