Canon Patent New High Speed AF EF-EF-M Adapter for EOS M mirrorless camera, as we all know that the Hybrid AF Sensor (phase+contrast based AF system) of the EOS M series camera work very well with the EOS-M native lenses aka EF-M mount lenses, but when EF or EF-S Lenses are mounted on EOS M series mirrorless via currently available adapter, we see slow and sluggish AF speed… to overcome this Canon patented High Speed AF EF-EF-M Adapter that will improve the AF speed while using the EF and EF-S Lenses.
Explanation self interpretation of patent literature
- Patent Publication No. 2015-34903
- Published 2015.2.19
- Filing date 2013.8.9
- Master lens
- Zoom ratio 2.69
- Focal length 72.13 135.02 193.99mm
- Fno. 2.90
- Half angle ω = 10.72 5.78 4.03 °
- Image height Y = 13.66mm
- Overall length of the lens 237.36mm
- BF 54.00mm
- Adapter installed
- Zoom ratio 2.69
- The focal length f = 72.12 135.00 193.96mm
- Fno. 2.90
- Half angle ω = 10.72 5.78 4.03 °
- Image height Y = 13.66mm
- Overall length of the lens 239.70mm
- BF 16.77mm
- Canon patent
- Fast AF adapter
- Wobbling corresponding
- 3-group configuration of positive and negative positive
- 2 group also serves as a focus group and the anti-vibration group
- And realize high-speed AF focus group was lighter
via – egami.blog.so-net.ne.jp
