Keith at Northlight has uncovered a patent showing optical formulas for three fast prime lenses, most notably a Canon RF 130mm f/1.4L USM. On my roadmap for Canon, we do have an RF 135mm f/1.4L USM listed, so this patent could potentially be related.
Canon RF 130mm f/1.4L USM
- Focal length: 131.00mm
- F-number: 1.41
- Angle of view: 9.38°
- Image height: 21.64mm
- Lens length: 182.28mm
- Backfocus: 13.87mm
The following optical design has a really strange backfocus distance of 54,12mm according to the patent literature.
Canon 135mm f/2L USM
- Focal length: 133.50mm
- F-number: 2.06
- Angle of view: 9.21°
- Image height: 21.64mm
- Lens length: 155.12mm
- Backfocus: 54.12mm
The following optical design also has an unusual backfocus distance.
Canon 24mm f/1.4L USM
- Focal length: 24.55mm
- F-nurnber: 1.45
- Angle of view: 41.39°
- Image height: 21.64mm
- Lens length: 119.13mm
- Backfocus: 38.01mm