Canon continues to work on focal length reducers.
What’s a focal length reducer you ask?
It’s an adapter that reduces the focal length of a lens and at the same time increases the maximum aperture, basically the opposite of teleconverters.
Canon has yet to release such a product, but we suspect this type of converter could benefit the EOS M system as well as an upcoming APS-C EOS R body.
Below are a bunch of focal length reduced optical formulas from Japan patent JP-A-2019-003074
Specification and lens arrangement of master lens 1 (18-55mm, F2.8)
Zoom ratio: 3.05
Focal length: 17.50 – 53.3 mm
F number: 2.80 – 2.80
Half angle of view: 36.65 – 13.71
Image height: 13.02 – 13.02mm
Lens length: 148.81 – 172.70mm
Back focus: 35.51 – 40.31mm
Specification and lens arrangement of master lens 1 with reducer 1
Focal length: 11.36mm
F number: 1.82
Half angle of view: 36.67...