Canon Patents

Patent: EF 20-45mm f/2.8-4

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

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