Canon field another two new lens patents in Japan. The two patents are:
- EF 100-400mm f/4.5-5.6
- EF 70-300mm f/4.5-5.6
There are several EF 100-400mm f/4.5-5.6 patents before, and we have heard that the EF 100-400mm f/4.5-5.6L IS II USM lens is coming soon, maybe announced along with the 7D Mark II.
Description and self-interpretation of the patent literature (Translated by Google)
- Patent Publication No. 2013-105053
- Publication date 2013.5.30
- Filing date 2011.11.15
- Example 1
- Zoom ratio 4.01
- Focal length f = 72.48-135.49-290.86mm
- Fno. 4.58-4.94-5.85
- Half angle ω = 16.62-9.07-4.25 °
- Image height Y = 21.64mm
- 143.42-175.48-201.87mm overall length of the lens
- BF 39.98mm
- Example 3
- Zoom ratio 3.75
- Focal length f = 104.16-166.66-391.00mm
- Fno. 4.60-5.20-5.80
- Half angle ω = 11.73-7.40-3.17 °
- Image height Y = 21.64mm
- 221.48-252.31-300.68mm overall length of the lens
- BF 70.65-87.69-113.37mm
- Canon patent
- I want to put in the first group the anomalous dispersion optical element
- It is possible correction and lateral chromatic axial chromatic aberration, but spherical aberration of color and field curvature occurs
- By optimizing the placement, the correction and field curvature, the spherical aberration of the color of g-line
via: EG