A patent showing continued development in EF mount optical formulas has appeared at the Japan Patent Office this past week.
This patent covers two optical formulas, one being an EF 20mm f/1.4 and the other being an EF 12-24mm f/4.5-5.6.
I don’t feel either of these optical formulas will become new products and this is more about the development of lens technologies than the optical formulas themselves.
Canon EF 20mm f/1.4
Focal length: 20.50mm
FNo: 1.44
Image height: 21.64mm
Lens length: 134.70mm
Back focus: 36.81mm
Canon EF 12-24mm f/4.5-5.6
Focal length: 12.40-18.00-23.64mm
FNo: 4.35-4.96-5.60
Image height: 21.64mm
Lens length: 142.18-132.82-131.14mm
Back focus: 36.14-44.23 -52.29mm
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