A patent for an optical formula of 20-45mm f/2.8-4 has appeared. As suggested at Northlight, this sort of optical formula could end up being a 17-40 type of replacement, or even part of the new EF 16-35 f/2.8L II development.
Patent Publication No. 2015-197593 (Google Translated)
- Published 2015.11.9
- Filing date 2014.4.1
- Zoom ratio 2.25
- Focal length f = 20.00 23.60 45.00
- Fno. 2.75 2.90 4.16
- Half angle of 47.25 42.51 25.68
- Image height 21.64 21.64 21.64
- Overall length 158.28 156.32 173.36
- BF 42.05 46.10 73.14