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Another patent
This is probably the third separate patent I have seen for an EF 100-400 f/4.5-5.6L IS over the last 24 months. A zoom ring version does exist in the wild. We're told the push/pull is finished and we'll get a properly sealed 100-400. The cost will be north of $2500 USD and we could finally see it announced before the end of the year. Also appearing in the patent is a 70-300.
The breakdown below is Google translated
- 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
Source: [EG]
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