Canon Patent: 20-120mm F4 And 18-100mm F4 For RF-S Mount

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A new Canon patent application (well, not really new) for two lenses for the RF-S mount.

Canon patent application 2023182926 (Japan, published 2023-12-27) discusses optical formulas for two RF-S mount lenses:

  • 20-120mm F4
  • 18-100mm F4

From the patent literature:

  • An object of the present invention is to provide a fixed-length zoom lens having a high zoom magnification and high optical performance over the entire zoom range.
  • BACKGROUND ART
    Fixed-length zoom lenses are known in which the overall length of the lens does not change during zooming. Such a zoom lens is suitable for video shooting and the like because the center of gravity does not change much during zooming. In recent years, zoom lenses have been required to have high zoom magnification and high optical performance over the entire zoom range for video applications.
  • However, although the zoom lens described in Patent Document 1 is superior in that there are fewer lens groups that move during zooming and focusing, improvements in optical performance are required as the resolution of sensors has increased in recent years
  • On the other hand, in the zoom lens described in Patent Document 2, high optical performance is obtained over the entire zoom range by increasing the number of lenses in each lens group, but an even higher zoom magnification is required.
  • The present invention provides a full-length fixed zoom lens having a high zoom magnification and high optical performance over the entire zoom range.

Example 1

  • Focal length: 20.02-119.95
  • F value: 4.08
  • Half angle of view: 34.40-6.31
  • Image height: 12.33-13.66
  • Total length: 165.00
  • Back focus: 13.54

Example 2

  • Focal length: 20.01-134.95
  • F value: 4.08
  • Half angle of view: 34.29-5.61
  • Image height: 12.33-13.66
  • Total length: 168.51-168.50
  • Back focus: 13.82

Example 3

  • Focal length: 18.41-101.96
  • F value: 4.08
  • Half angle of view: 36.59-7.42
  • Image height: 12.33-13.66
  • Total length: 146.50146.49
  • Back focus: 13.77

[via asobinet]

Canon Patent: 18-100mm F4 And 14-60mm F4 Lenses

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Another Canon patent application today, for a 18-100mm f/4 lens and a 14-60mm f/4 lens.

Canon patent application 2023018409 (Japan, published 2/8/2023) discusses optical formulas for two lenses we think are for the RF mount, 18-100mm f/4 and a 14-60mm f/4.

From the patent literature:

To provide a zoom lens that is compatible with a short back and suppresses variations in optical performance due to focusing in a wide-angle range with a wide angle of view.

Description of the Related Art

There is a demand for a compact and lightweight zoom lens compatible with a so-called mirrorless camera without a quick return mirror. For example, it consists of a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group including a plurality of lens groups, arranged in order from the object side to the image side, and the second lens group is the main lens group. A zoom lens with a variable power group is known (.

Further, in recent years, in order to reduce the size of the zoom lens, an imaging apparatus has been proposed that electrically corrects distortion mainly in a wide-angle range among various aberrations of a zoom lens. However, in such an image pickup apparatus, field curvature fluctuations, in particular, become large as aberration fluctuations during focusing.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a zoom lens that is compatible with shortback and suppresses fluctuations in optical performance due to focusing in a wide-angle range with a wide angle of view, and an imaging apparatus and an imaging system having the zoom lens.

Example 1

  • Focal length: 15.45-68.00
  • F-value: 4.12
  • Half angle of view: 36.92-11.36
  • Total length: 106.58-125.20
  • Back focus: 10.68-12.16

Example 2

  • Focal length: 13.40-63.10
  • F-value: 4.12
  • Half angle of view: 40.91-12.22
  • Overall length: 105.91-129.46
  • Back focus: 11.16

Example 3

  • Focal length: 18.00-88.20
  • F-value: 4.12
  • Half angle of view: 32.82-8.80
  • Total length: 108.02-127.32
  • Back focus: 11.42

More Canon patent applications are listed here.

[via asobinet]

Canon patent for EF-S 18-100mm f/3.5-5.6 IS STM lens for APS-C sensors

ef-s 18-100mm

A patent does neither mean that a company is actively working on the described product, nor it is a warranty we’ll ever see the described product. However, here is another patent for a STM lens for APS-C DSLRs filed by Canon.

The patent refers to a EF-S 18-100mm f/3.5-5.6 IS STM lens,. 18-100mm is a sonewhat unusual focal range, even more if you consider that Canon has the excellent EF-S 18-135mm f/3.5-5.6 IS STM on offer.

  • Patent Publication No. 2016-1224
    • Published 2016.1.7
    • Filing date 2014.6.11
  • Example
    • Focal length 18.59 47.22 94.99
    • F-number 3.60 4.92 5.88
    • Half angle of view (degrees) 36.31 16.14 8.18
    • Image height 13.66 13.66 13.66
    • The total lens length 137.78 158.04 178.30
    • BF 35.39 52.79 64.61

[via Egami]