Cytat:
Canon EF 17-40 f/2.8-4L Patent
Below is a patent for a new Canon wide angle zoom concept. The variable aperture is interested, if it remained as light and compact as the current 17-40 f/4L, the additional stop of light wide open would be a nice feature.
Patent Publication No. 2010-42792
2012.3.1 Release Date
2010.8.20 filing date
Example 1
39.05mm – f = 17.64 focal length
Fno = 2.64 – 4.10
28.99 deg – 50.80 half angle of view.
Image height 21.64mm
136.70mm – 134.67 full-length lens
BF 39.97 – 64.95mm
Lens Construction 12 elements in 9 groups sheet
4 aspherical surface