A slew of patents showing various wide angle optical formulas has appeared. All of the lenses appear to be for full frame and could be hints of replacements for the EF 17-40 f/4L as well as the EF 16-35 f/2.8L II.
- Patent Publication No. 2014-41245
- Publication date 2014.3.6
- Filing date 2012.8.22
- Example 1
- Focal length f = 16.49-23.55-33.95mm
- Fno. 4.10
- Half angle ω = 52.68-42.57-32.51 °
- 14 pieces of 10-group lens configuration
- Example 2
- Focal length f = 17.50-25.45-38.90mm
- Fno. 4.10
- Half angle ω = 51.03-40.36-29.08 °
- 15 pieces of 11-group lens configuration
- Example 4
- Focal length f = 17.50-24.82-38.89mm
- Fno. 2.88-3.25-4.10
- Half angle ω = 51.02-41.08-29.09 °
- 15 pieces of 11-group lens configuration
- Example 5
- Focal length f = 16.50-25.34-34.00mm
- Fno. 2.91
- Half angle ω = 52.66-40.49-32.47 °
- 15 pieces of 11-group lens configuration
- Canon patents
- 4-group zoom of positive and negative positive negative
- Inner focus
Source: [EG]
Canon EF 17-40 f/4L | Canon EF 16-35 f/2.8L II
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