Canon has filed a new patent application for two RF-mount telephoto lenses with extender: 200-400mm F4 x 1.4 and 200-500mm F4 x 1.4. lenses. Designed for Canon RF-mount full-frame mirrorless cameras, Canon patent application P2022185663 (Japan, published 12/15/2022) discusses optical formulas for two RF-mount telephoto lenses with 1.4 extender, the RF 200-400mm F4 x 1.4 and RF 200-500mm F4 x 1.4.
Example 1
- Focal length: 205.1-385.5
- F-value: 4.1
- Half angle of view: 5.99-3.21
- Image height: 21.635
- Total length: 367.62
- Back focus: 39.994
Example 2
- Focal length: 290.4-543.2
- F-value: 5.8
- Half angle of view: 4.26-2.28
- Image height: 21.635
- Total length: 367.62
- Back focus: 39.994
Example 3
- Focal length: 207.0-487.9
- F-value: 4.1
- Half angle of view: 5.97-2.54
- Image height: 21.635
- Overall length: 410.05
- Back focus: 39.998
Example 4
- Focal Length: 288.1-678.9
- F-value: 5.7
- Half angle of view: 4.30-1.83
- Image height: 21.635
- Overall length: 410.05
- Back focus: 39.998