Firmware Upgrades For Wireless Transmitter WFT-E5A And 4 Lenses

Canon has recently released two new product advisories. The first one concerns the WFT-E5A Wireless Transmitter. The firmware upgrade (ver. 1.0.7) doesn’t tackle problems or malfunctions, it was released to support the just released, massive firmware update for the EOS 7D.

Next, Canon also released a product advisory for the following lenses: EF 300mm f/2.8L IS II USM, EF 400mm f/2.8L IS II USM, EF 500mm f/4L IS II USM, and EF 600mm f/4L IS II USM. The firmware update (ver. 1.1.1) will be performed by Canon Service Centers and brings the following enhancement:

Changes the control algorithm of the focus drive, and enhances the drive’s responsiveness for more precise focus and adjustments. In particular, the new firmware enhances the AI servo AF capability of the lenses to track objects that move irregularly in sports events, such as soccer or rugby.

[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]