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Showing posts with label EF Macro DO. Show all posts
Showing posts with label EF Macro DO. Show all posts

Monday, July 28, 2014

Canon EF 180mm f/3.5 DO Macro Lens


Canon EF 180mm f/3.5 DO Macro Lens?

Egami, the Japanese photography blog has uncovered a Canon patent for the EF 180mm f/3.5 DO Macro lens. Frankly, I am puzzled by this design. The current EF 180mm f/3.5L is a slow lens but it's not heavy. If I were Canon, I'd make the lens faster and add IS instead of making it smaller and lighter. But then it's only a patent. Many patents never make it to the market anyway.

    Patent Publication No. 2014-137484

  •         Published Date 2014.7.28
  •         Filing date 2013.1.17

    Example 1

  •         Focal length f = 180.00mm
  •         Shooting magnification ? 0.5x 1.0x
  •         Fno. 3.50-4.50-5.20
  •         Half angle ? = 6.85 °
  •         Image height 21.64mm
  •         The overall length of the lens 202.38mm
  •         BF 52.18mm
  •         Effective diameter of the front lens 58.18mm
  •         12 sheets 8 groups lens configuration