Canon patent for 20-45mm f/2.8-4 lens

20-45mm

Canon filed a patent for a 20-45mm f/2.8-4 lens. Somewhat unusual specs, but who knows.

  • Patent Publication No. 2015-197593
    • Published 2015.11.9
    • Filing date 2014.4.1
  • Example
    • 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
[via Egami]