After Canon Patent News: 500mm f/4 DO, 500mm f/5.6 DO, 600mm f/4 DO, 800mm f/5.6 DO Lenses patent and Canon Patents 70-300mm, 100-400 mm F4.5-5.6 DO Lens Patent now we have Canon EF 400 f/4 DO IS patent information, it has been really a long time since we have seen any real DO lens announcement.
Canon Patent Details Translated by Google
- Patent Publication No. 2014-109700
- Publication date 2014.6.12
- Filing date 2012.12.3
- Example 1
- Focal length f = 392.00-381.59-332.99mm
- Fno.
- Half angle ω = 3.16-3.10-2.81 °
- Image height Y = 21.64mm
- The overall length of the lens 292.02mm
- BF 105.64mm
