I spent the past few days researching Fast Wide Angle Primes for the m4/3 cameras. I will use this thread as a summary.
C-mount lenses are available for upto a 1-inch sensor and vignetted heavily at lengths less than 25mm.
35mm fisheyes like Peleng and Samyang 8mm/f3.5 allow a 16mm field of view but need lots of light (it becomes a 16mm f7.0).
So I looked at some other options. An obvious check is to find lenses for sensors greater than 1-inch.
It turns out that the Kodak Kai-4021 sensor is 1.2-inch. Its close enough to the 1.33" m4/3 sensor.
Kodak Kai 4021 based cameras are popular in astronomy applications.
Here are some pics of this sensor with unidentified lenses..
I simple search for Kai 4021 lens on google.
So now perhaps we could have a group effort in identifying lenses for such cameras.