Keith over at Northlight Images has uncovered a patent at the USPTO that shows Canon working on a lot of fast RF prime lenses.
The optical formulas in this patent include:
- Canon RF 50mm f/1.8
- Canon RF 80mm f/1.4
- Canon RF 85mm f/1.4
- Canon RF 85mm f/1.8
- Canon RF 100mm f/2
- Canon RF 135mm f/2
- Canon RF 300mm f/2.8
These obviously won't all become consumer products, but I think it shows Canon is working on longer fast primes for the RF mount.