Canon filed a new patent for 400mm f/4 DO IS Extender 1.4x and 600mm f/4 IS Extender. Canon patent application 2022-22771 discusses optical formulas for RF mount mirrorless cameras. First of all the lenses ;
- 400mm f/4 DO IS Extender 1.4x
- 600mm f/4 IS Extender 1.4x
See the details of the 400mm f/4 DO IS Extender 1.4x and 600mm f/4 IS Extender below.
Example 1
- Focal length: 392.58
- F value: 4.12
- Half angle of view: 3.15
- Image height: 21.64
- Overall length: 280.33
- Back focus: 36.01
Example 1 (with inserted teleconverter)
- Focal length: 549.72
- F value: 5.77
- Half angle of view: 2.25
- Image height: 21.64
- Overall length: 280.33
- Back focus: 36.00
Example 5
- Focal length: 585.00
- F value: 4.12
- Half angle of view: 2.12
- Image height: 21.64
- Overall length: 467.45
- Back focus: 55.50
Example 5 (with inserted teleconverter)
- Focal length: 819.18
- F value: 5.77
- Half angle of view: 1.51
- Image height: 21.64
- Overall length: 467.45
- Back focus: 55.50
The Canon patent application was spotted by asobinet.com.