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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
- Image height: 8.46mm
- Lens length: 142.26mm
- Back focus: 2.00mm
Specification and lens arrangement of master lens 2 (34mm, F1.4)
- Focal length: 34.20mm
- F number: 1.45
- Half angle of view: 32.32
- Image height: 21.64mm
- Lens length: 129.16mm
- Back focus: 39.35mm
Specification and lens arrangement of master lens 2 with reducer 5
- Focal length: 23.92mm
- F number: 1.02
- Half angle of view: 32.33
- Image height: 15.14mm
- Lens length: 125.59mm
- Back focus: 2.00mm
