Canon Patent: RF-S 10-14mm F3.5-4 Lens For APS-C

Canon Patent

After a long time, here is a new Canon patent application.

Canon patent application 2023066202 (Japan, published 5/15/2023) discusses optical formulas for a RF-S 10-14mm F3.5-4 lens, i.e. a lens for the RF-mount and APS-C imaging sensors.

From the patent literature:

An object of the present invention is to provide a zoom lens capable of reducing the occurrence of ghost while having high optical performance.

BACKGROUND OF THE INVENTION

Field of the Invention The present invention relates to zoom lenses and the like, and is suitable for imaging devices such as digital video cameras, digital still cameras, broadcast cameras, and silver halide film cameras.
Description of the Related Art

Wide-angle lenses are widely used for landscape photography, astrophotography, and the like. A wide-angle lens is required to achieve high optical performance while widening the angle of view.
In the zoom lens disclosed in Patent Document 1, since the opening angle of the first lens is large, unwanted light reflected obliquely from the lens surface of the second lens on the object side becomes an image of the first lens. It was sometimes reflected on the lens surface on the side and reached the image plane. When such unnecessary light reaches the image plane, it is undesirable because it causes a ghost image on the photograph.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a zoom lens capable of reducing the occurrence of ghost while having high optical performance.

Example 1

  • Focal Length: 15.45-29.15
  • F-value: 4.60-6.32
  • Half angle of view: 49.36-36.19
  • Image height: 18.00-21.33
  • Overall length: 115.26-107.01
  • Back focus: 13.50

Example 2

  • Focal length: 9.97-14.64
  • F-value: 3.50-4.23
  • Half angle of view: 49.63-41.54
  • Image height: 11.72-12.97
  • Overall length: 72.73-71.78
  • Back focus: 10.06-14.3

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

[via asobinet]