Canon has just filed a new lens patent: RF 8mm f/4 Fisheye lens, this will be first fisheye lens for Canon RF mount.
Embodiment 1
Focal length: 8.10 mm
F number: 4.00
Half angle of view: 90.84
Image height: 11.50 mm
Lens length: 66.13 mm
Back focus: 13.21 mm