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Saturday, September 21, 2013

Canon Patent EF 24-70mm f/2.8L IS Lens




Egami, the Japanese Photography blog has uncovered Canon patents for a EF 24-70mm f/2.8L IS and a EF 24-80mm f/2.8L IS lenses. You can read the (translated) article here. The recently introduced EF 24-70mm f/2.8L II lens lacks Image Stabilization and is not a very good value for the money even though the lens is a top performer.

Patent Publication No. 2013-182246

  • Publication date 2013.9.12
  • Filing date 2012.3.5


Example 1

  • Zoom ratio 2.75
  • Focal length f = 24.70-36.42-67.88mm
  • Fno. 2.91
  • Half angle ω = 41.22-30.71-17.68 °
  • Image height 21.64mm
  • 164.87-172.85-196.79mm overall length of the lens
  • BF 39.07-44.44-54.56mm
  • 20 pieces of 13-group lens configuration
  • Four four-sided aspherical


Example 2

  • Zoom ratio 2.76
  • Focal length f = 24.70-34.88-68.18mm
  • Fno. 2.91
  • Half angle ω = 41.22-31.81-17.61 °
  • Image height 21.64mm
  • 165.79-174.26-199.67mm overall length of the lens
  • BF 38.47-42.81-58.00mm
  • 20 pieces of 15-group lens configuration
  • Three 3 aspherical surface


Example 3

  • Zoom ratio 3.22
  • Focal length f = 24.70-39.67-79.43mm
  • Fno. 2.91
  • 41.22-28.61-15.24 ° angle of view
  • Image height 21.64mm
  • 161.98-171.74-200.99mm overall length of the lens
  • BF 38.35-46.17-57.64mm
  • 20 pieces of 13-group lens configuration
  • Four four-sided aspherical


Canon patent

  • 5-group zoom of positive and negative positive positive and negative
  • Antivibration (fourth lens group)

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