The famous AEG Weitwinkelobjektiv 6.3/1.7cm,
a fisheye lens conceived by the AEG - Berlin during 1935 for meteorological purposes (clouds recording),
this lens was claimed for an angle of view exceeding 180° (the CADO memos suggest 200°) and it's optical formula is a true benchmark,
the mother of all modern fisheye lenses. The optical sketch of the AEG fisheye represents the embryo of modern fisheye lenses,
it's formula was immediately shared with the Nippon Kogaku's technicians and in their first fisheye camera, released in 1938,
the Fisheye Nikkor 8/16.3mm was a true clone of the AEG lens,
and the first Fisheye Nikkors for the Nikon F outfit (like the 8/8mm and 5.6/7.5mm)
shared obvious analogies with the original AEG and Nikkor fisheye lenses.
I only know one photographer who mades pictures with this camera and only a view of them exist today.
This is the artist Otto Umbehr (UMBO).
Please also see the original patent certification regarding the "AEG-Weitwinkelobjektiv"!
Patented on 06.08.1932. The publication about the patent was on 03.10.1935.
The optic caltulator could be Dr. Hans Schulz probably.
Authority: "Patent number DE 620538"