Here is another Canon patent application for a bunch of fast prime lenses for the RF mount. Canon full frame mirrorless system is growing and we see quite more patents for this mount.
Keep in mind that the mere existence of a patent application doesn’t necessarily entail the described item will ever hit the market. So we might see changes when it comes to mass production.
Canon patent application 2021-193406 (Japan) aims to
[…] provide an optical system having high optical performance and less aberration fluctuation due to focusing.
and discusses optical formulas for these lenses:
- RF 18mm F1.8
- Focal length 18.54
- F number 1.85
- Half angle of view (°) 49.41
- Image height 21.64
- Lens total length 107.66
- BF 14.09
- RF 20mm F1.4
- Focal length 20.48
- F number 1.44
- Half angle of view (°) 46.56
- Image height 21.64
- Lens total length 124.66
- BF 13.16
- RF 24mm F1.8
- Focal length 23.83
- F number 1.85
- Half angle of view (°) 42.24
- Image height 21.64
- Lens total length 104.66
- BF 15.90
- RF 28mm F1.8
- Focal length 28.08
- F number 1.85
- Half angle of view (°) 37.61
- Image height 21.64
- Lens total length 92.66
- BF 12.16