skip to Main Content

[Patent] Canon Files Patent For 600mm f/5.6 and 800mm f/5.6

600mm f/5.6 DO
800mm f/5.6 DO

Egami (machine translated) found a patent filed by Canon for a 600mm and a 800mm f/5.6 lens using diffractive optical elements.

  • Patent Publication No. 2012-123152
    • 2012.6.28 Release Date
    • 2010.12.8 filing date
  • Example 1
    • Focal length f = 584.99mm
    • Fno. 5.80
    • Half angle of 2.12 deg.
    • Image height 21.64mm
    • Length 360.03mm
    • BF 94.84mm
    • 17 pieces in 10 groups Lens Construction
    • 3 UD glass sheet
    • One fluorite
    • A surface diffraction plane
  • Example 3
    • Focal length f = 779.00mm
    • Fno. 5.80
    • Half angle of 1.59 deg.
    • Image height 21.64mm
    • Length 462.02mm
    • BF 120.29mm
    • 17 pieces in 10 groups Lens Construction
    • 2 UD glass sheet
    • Two fluorite
    • A surface diffraction plane
  • Low dispersion material with anomalous partial dispersion
    • To be effective in the correction of chromatic aberration
    • Specific gravity is large (heavy)
      • 3.18 fluorite
      • FK01 3.63
      • The specific gravity of small anomalous partial dispersion glass material
        • FK5 2.46
        • BK7 2.52
    • Surface may be damaged easily
    • FK01 is fragile due to temperature changes and large diameter
  • Diffractive optical element (DOE)
    • To be effective in the correction of chromatic aberration
    • Is generated by unwanted light flare and ghosting
  • Canon’s patented
    • Become positive from negative to DOE
    • DOE to place the position is hard to unwanted light incident
Back To Top

Notice

This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purposes illustrated in the cookie policy. If you want to know more or withdraw your consent to all or some of the cookies, please refer to the cookie policy.
By closing this banner, scrolling this page, clicking a link or continuing to browse otherwise, you agree to the use of cookies.