Archive for: Canon EF 35 f/1.4L II

Patent: Canon EF 35 f/1.4L II

Canon EF 35 f/1.4L Patent
A new patent for a 35mm f/1.4 optical formula has appeared. This is the first to appear since 2011 in regards to an updated 35 f/1.4L. View the previous patent here.

Canon EF 35 f/1.4L II?

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
  • 2 UD glass sheet

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

Source: [EG]

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