[Patent] Canon Files Patent For A New 35mm f/1.4 Prime Lens

Egami (machine translated) spotted a new Canon patent. This time it is for a 35mm f/1.4 prime lens. The existing EF 35mm was released in 1998, so it makes sense for Canon to work on a new release of this lens. According to Egami, it looks as if Canon has been working since four years on this lens.

Details (machine translated):

• Patent Publication No. 2012-123155
  • 2012.6.28 Release Date
  • 2010.12.8 filing date
• Example 1
  • Focal length f = 34.73mm
  • Fno. 1.45
  • Half angle of 31.92 deg.
  • Image height 21.64mm
  • Length 128.11mm lens
  • 38.48mm back focus
  • An effective diameter of 52.03mm lens
  • Effective diameter aperture 25.52mm
  • Lens Construction 12 elements in 9 groups sheet
  • 2 2 aspherical surface
• Retrofocus
  • And retro focus lens optical system focal length is shorter than the length of the optical system
  • Increasingly asymmetric refractive power arrangement must be strengthened a negative refractive power of the front group in particular
    • Coma aberration, astigmatism, spherical aberration occurs
  • Order to secure a back focus must be to increase the ratio retro
    • Pettsuvu~aru sum is reduced and off-axis aberration (field curvature, distortion) is worse