[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

[Review] Canon EF 600mm f/4L IS II

canonrumors reviewed Canon’s long awaited EF 600mm f/4L IS II. Impressions are very good. From the verdict:

On the surface, Canon has produced the best designed 600mm lens in their history and maybe ever. The weight savings alone are a monumental achievement. Everything else about the lens is high end, from optical performance to autofocus and build quality.

There are sample images provided. The EF 600mm f/4L IS II has a price tag of $12,999 and can be pre-ordered at the following shops:

 

Canon EF 500mm f/4L IS II USM & EF 600mm f/4L IS II USM Available for Pre-Order (Update)

Canon 500mm f/4L EF IS II USM Lens

Update: Adorama also has both lenses ready for pre-order.

Announced in February, the EF 500mm f/4L IS II USM ($10,499 click here) and the EF 600mm f/4L IS II USM ($12,999 click here) are finally ready for pre-order at B&H. See the press release, and here for more detailed specs.

In short:

  • EF 500mm f/4L IS II USM:

    • Redesigned Fluorite Optics
    • Less Chromatic Aberration
    • Magnesium/Titanium for Lighter Weight
    • 3 IS Modes for 4-Stop Advantage
    • Smooth Focus Change for Video
    • Redesigned, Intuitive Buttons/Switches
  • EF 600mm f/4L IS II USM:
    • Fluorite Optics for Sharper Images
    • Less Chromatic Aberration
    • Magnesium/Titanium for Lighter Weight
    • 3 IS Modes for 4-Stop Advantage
    • Smooth Focus Change for Video
EF 600mm f/4L IS II USM Telephoto Lens

[Patent] Canon’s New EF 600mm f/4 and EF 400mm f/2.8 Lenses

600mm f/4
400mm f/2.8

Japanese site egami (Google translated) spotted two new Canon patents. The patents refer to the EF 600mm f/4 and the EF 400mm f/2.8 lenses. The lenses will have reduced size and weight. The 600mm will have 15 elements in 9 groups, the 400mm 14 elements in 9 groups (more specs below). Performance charts:

Performance Chart 600mm f/4
Performance Chart 400mm f/2.8

More specifications (machine-translated)…:

  • Patent Publication No. 2012-88427
    • 2012.5.10 Release Date
    • 2010.10.18 filing date
  • Example 1
    • Focal length f = 585.00mm
    • Fno 4.12
    • Image height 21.64mm
    • Length 468.50mm lens
    • BF 90.78mm
    • 15 sheets of 9 group lens configuration
    • One aspherical surface a
    • 2 UD glass sheet
    • One fluorite
    • A plane diffraction
  • Example 2
    • Focal length f = 391.86mm
    • Fno 2.88
    • Image height 21.64mm
    • Length 367.51mm lens
    • BF 50.01mm
    • Lens Construction 14 elements in 9 groups sheet
    • 2 2 aspherical surface
    • 1 UD glass sheet
    • One fluorite
    • A plane diffraction
  • Group 3 consists of positive and negative positive
  • Inner Focus (group 2)
  • Strengthen the refractive power of the front lens group, and to shorten the overall length, the sensitivity is increased, it is difficult to manufacture and assembly
  • The number of lens group at the end of the super-telephoto lens is determined by the balance of the total length and chromatic aberration
    • And shorten the length and reconcile, the correction of chromatic aberration, the number will increase
      • It is important to the length of each degree
    • Weight of the first lens group, 70% to 9 on the whole
      • Canon patents is reduced to three the first group
      • Aspherical and one eye in group 1 group, field curvature correction, the distortion
      • Diffractive optical element and the second two groups in the first group, the chromatic aberration correction
[egami via CR]