Egami discovered a new patent filed by Canon in Japan. The new patent describes a Canon EF 70-400 f/4.5-5.6L IS telephoto zoom lens. This new lens could be announced by the end of 2014 and will be a good replacement for the current EF 100-400mm f/4.5-5.6L IS USM lens model.
Canon EF 70-400mm f/4.5-5.6L IS lens is 240mm in overall length and provide a zoom of 5.45x. Focal range is between 71.33mm and 388.95mm. The lens design as we see from the patent details shows multiple elements divided in 6 groups.
Canon Patent for EF 70-400mm f/4.5-5.6L IS Lens
Description and self-interpretation of the patent literature
- Patent Publication No. 2014-21256,2014-21257
- Publication date 2014.2.3
- Filing date 2012.7.18
- Example 2
- Zoom ratio 5.45
- Focal length f = 71.33-144.71-388.95mm
- Fno. 4.63-4.84-5.83
- Half angle ω = 16.87-8.50-3.18 °
- Image height Y = 21.64
- 240.00-284.68-303.83mm overall length of the lens
- BF 75.92-79.30-95.93mm
- 6-group zoom of positive and negative positive and negative positive and negative
- (Part of the fourth group) anti-vibration
- Rear Focus (Group 6)
via EG
