New Canon 35mm f/1.4 Prime Lens Patent

Egami spotted a Canon patent for new 35mm f/1.4 prime lens. The existing EF 35mm was released in 1998, so it makes sense for Canon to refresh this lens. According to Egami, it looks as if Canon has been working since four years on this lens.

Features (translated by google):

  • 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