The lens was a rebranded Mamiya 14mm fisheye for the Voigtlander VSL with QBM mount, it was intended as a cheaper alternative for the 16mm Zeiss F-Distagon f/2.8, and it was also rebranded with a different finish and look for the Rollei cameras. It was part of foolish Rollei policy having a confusion of brands, names etc. It’s full metal construction with apertures going from 3.5 to 16.
It sports a filter turret, the control is nicely built within the hood. I’d like to know which filters were available.
in VR panoramic photography use:
Equidistant projection, effectively a 14,17 mm focal lenght. It gives a 23500 x 11750 panorama on A7R4, can do 6 around, 5 or even 4 with a small overlap, allows a -20 (extreme -30) pitch. at first seems incredibly sharp.