Translate this blog into your language

Saturday, May 24, 2014

Canon Patent : EF 100-400mm f/4.5-5.6 DO

Egami, the Japanese photography blog, has discovered a new Canon patent for the EF 100-400mm f/4.5-5.6 lens using Diffractive Optics technology. The patent also shows what appears to be a new EF 70-300mm f/4.5-5.6 DO lens as well.

I am a big supporter of Canon's Diffractive Optics technology. The current EF 400mm f/4 DO IS is one of my favorite Super Telephoto lenses in their lineup. Although not among the sharpest glass, its light weight, mobility and versatility more than offset the 'disadvantages' for my wildlife photography. In the past, I have advocated that Canon should continue to innovate in their DO research because it gives them an unmatched advantage over their competitors.

The EF 100-400mm f/4.5-5.6L IS II is scheduled to be announced some time in August and the present EF 70-300mm f/4-5.6L IS lens is selling well. However, there are new patents utilizing the DO technology discovered on the EF 400mm f/4 DO IS II and 600mm and 800mm lenses. Visit my website to see photos taken with the EF 400mm f/4L DO IS lens. Hopefully, Canon will delight me in the future by announcing more DO lenses.

Patent Publication No. 2014-89385

  • Publication date 2014.5.15
  • Filing date 2012.10.31

Example 1

  • Zoom ratio 3.78
  • Focal length f = 103.00-200.00-388.94mm
  • Fno. 4.63-5.24-5.83
  • Half angle ? = 11.86-6.17-3.18 °
  • Image height Y = 21.64mm
  • 228.82-273.58-303.10mm total length
  • BF 69.48-90.93-105.73mm

Example 6

  • Zoom ratio 4.00
  • Focal length f = 72.50-135.00-289.99mm
  • Fno. 4.44-5.04-5.85
  • Half angle ? = 16.62-9.10-4.27 °
  • Image height Y = 21.64mm
  • 143.91-177.69-203.15mm total length
  • BF 39.10-39.10-39.10mm

No comments: