Canon Patent: 15mm F4.5 And 10mm F3.5 For APS-C Mirrorless
And here is one more Canon patent. Canon patent application 2024006604 (Japan, published 01/17/2024) discusses optical formulas for two wide prime lenses for mirrorless cameras with an APS-C imaging sensor.
- 15mm F4.5
- 10mm F3.5
From the patent literature:
- An object of the present invention is to provide an optical system that can reduce the occurrence of ghosts while having high optical performance.
- BACKGROUND ART: Wide-angle lenses are widely used for landscape photography, astronomical photography, and the like. Wide-angle lenses are required to have a wide angle of view and high optical performance.
- Patent Document 1 discloses an optical system that has a wide angle of view and improved optical performance by employing a plurality of negative lenses on the object side to gently bend off-axis rays. ing.
Example 1
- Focal length: 15.45
- F value: 4.60
- Half angle of view: 49.36
- Image height: 18.00
- Total length: 115.26
- Back focus: 13.50
Example 2
- Focal length: 9.97
- F value: 3.50
- Half angle of view: 49.63
- Image height: 11.72
- Total length: 72.73
- Back focus: 10.06
Example 3
- Focal length: 16.00
- F value: 4.60
- Half angle of view: 48.58
- Image height: 18.14
- Total length: 99.94
- Back focus: 13.04
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