That patent train continues for EF-M lens optical formulas, this time we see a 50-300mm f/4.5-5.6 DO lens for APS-C sized sensors. This optical formula patent shows the lens for both EF-M and EF-S mounts. It's definitely interesting to see diffractive optics development for consumer grade cameras.
Patent Publication No. 2016-57444 (Google Translated)
- Published 2016.4.21
- Filing date 2014.9.9
Example 1
- Zoom ratio 5.59
- Focal length 51.77 135.00 289.53
- F-number 4.65 5.05 5.85
- Half angle of view (degrees) 14.78 5.78 2.70
- Image height 13.66 13.66 13.66
- The total lens length 126.05 169.37 184.15
- BF 35.50 35.50 35.50
Example 2
- Zoom ratio 5.90
- Focal length 49.13 135.00 290.00
- F-number 4.65 4.95 5.85
- Half angle of view (degrees) 15.54 5.78 2.70
- Image height 13.66 13.66 13.66
- The total lens length 108.00 152.12 168.00
- BF 15.69 15.69 15.69
We have yet to see any full frame optical formulas for a full frame mirrorless camera body. We don't find this surprising as we expect any such camera be compatible with EF lenses.