Update: Canon News has dug a bit further and come to the conclusion that these optical formulas are for a fisheye due to the lenses having a 175 degree field of view.

A new patent showing an optical formula for a new wide angle prime has appeared. The full frame lens in the application is an EF 15mm f/4, while the APS-C optical formula of a EF-M 9.5mm f/4 shows a shorter backfocus than an EF-S lens and could actually be EF-M.

Japan Patent Application 2018-004726

Canon EF-M 9.5mm f/4

  • Focal distance 9.50
  • F number 4.10
  • Imaging field angle (degree) 175
  • Image height 13.66
  • Whole length of the lens 63.97
  • BF 23.16

Canon EF 15mm f/4

  • Focal distance 15.18
  • F number 4.12
  • Imaging field angle (degree) 175
  • Image height 21.64
  • Whole length of the lens 130.16
  • BF 58.19
Some of our articles may include affiliate links. If you purchase through these links, we may earn an affiliate commission at no extra cost to you.

Comments are closed.