Canon Patent: 800mm f/5.6 IS, 1000mm f/8 IS And 1200mm f/8 IS Lenses

Canon Patent

A new Canon patent application. Canon patent application 2023107573 (Japan, published 8/3/2023) discusses optical formulas for three telephoto lenses:

  • 800mm f/5.6 IS
  • 1000mm f/8 IS
  • 1200mm f/8 IS

From the patent literature:

An object of the present invention is to provide an optical system in which various aberrations are satisfactorily corrected while being compact and lightweight, and an imaging apparatus having the optical system.

Description of the Related Art

A telescopic optical system used in an imaging apparatus is required to have a long focal length and a small F-number (large aperture). Patent Documents 1 and 2 disclose a first lens group with positive refractive power, a second lens group with positive or negative refractive power, and a third lens group with positive or negative refractive power, which are arranged in order from the object side to the image side. An optical system is disclosed, consisting of lens groups, with a second lens group moving during focusing.

Here, it is also desired that the telescopic optical system be compact and lightweight, and that various aberrations such as chromatic aberration and spherical aberration are well corrected. However, when trying to increase the aperture of a telescopic optical system, the effective diameter of the lens arranged on the object side becomes particularly large, making it difficult to reduce the size and weight of the entire system. Therefore, in order to realize the above-mentioned demands, it is important to appropriately set the optical arrangement of each lens group that constitutes the optical system, and the refractive power and arrangement of each lens that constitutes each lens group.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an optical system in which
various aberrations are satisfactorily corrected while being compact and lightweight, and an imaging apparatus having the optical system.

Example 1

  • Focal length: 820.00
  • F-value: 5.90
  • Half angle of view: 1.51
  • Image height: 21.64
  • Total length: 437.08
  • Back focus: 88.12

Example 2

  • Focal length: 1180.10
  • F-value: 8.00
  • Half angle of view: 1.05
  • Image height: 21.64
  • Total length: 550.00
  • Back focus: 140.36

Example 3

  • Focal length: 1000.0
  • F-value: 8.00
  • Half angle of view: 1.24
  • Image height: 21.64
  • Total length: 477.48
  • Back focus: 115.01

More Canon patents are listed here.

[via asobinet]

Canon EF 1000mm F5.6 DO lens coming, filed patent suggests [CW3]

ef 1000mmm F5.6

Among all the patents filed by Canon, this may be one that actually could hit the market (in my opinion). The patent refers to an EF 1000mm F5.6 DO (Diffractive Optics) lens. Would be perfect for the upcoming Olympic Games :-) Who knows…maybe Canon is already field-testing this lens.

  • Patent Publication No. 2016-102852
    • Published 2016.6.2
    • Filing date 2014.11.27
  • Example
    • Zoom ratio 1.00
    • Focal length 950.00
    • F-number 5.80
    • Angle of view 1.30
    • Image height 21.64
    • Overall length of the lens 485.94
    • BF 0.40
  • Canon¬†patent
    • Positive and negative Shibomake
    • Diffractive optical element (first group)
    • Inner focus (the second group)

[via Egami]