Canon Photography News and Rumors

Canon filed patents for 400-600mm F2.8-4, 300-600mm F2.8-4.5, and 70-300mm F4 lenses.

overview

• [Publication number] P2024101302
• [Release date] 2024-07-29
• [Name of invention] Zoom lens and imaging device and imaging system having the same
• [Application date] 2023-01-17
• [Applicant]
  [Identification number] 000001007
  [Name or company name] Canon Inc.
• A zoom lens that is small in size and has a large aperture while still providing high optical performance.
• [Background Art]
  [0002]
  In recent years, there has been a demand for a telephoto lens with a zoom function, which is small and has a large aperture, yet has high optical performance. Patent Document 1 discloses an optical system having a plurality of converter lenses, which is composed of a first to third lens group with positive, negative, and positive refractive powers, and a subsequent group including one or more lens groups, which are arranged in order from the object side to the image side, in order to achieve weight reduction and telephotography. Patent Document 2 discloses an optical system having a first and second lens group with positive and negative refractive powers, and a subsequent group including one or more lens groups, which are arranged in order from the object side to the image side, in order to achieve both size reduction and high image quality, and the first lens group is composed of a plurality of subgroups. Patent Document 3 discloses an optical system having a first lens group with positive refractive power, a second lens group, and a subsequent group including one or more lens groups, which are arranged in order from the object side to the image side, in order to achieve both improved optical performance and weight reduction, and which ensures an air gap in the first lens group.
• [0004]
  However, in the optical system of Patent Document 1, the refractive power of the first lens group and the second lens group are optimized to achieve compactness, and it is also possible to achieve telephotography using multiple converter lenses, but it is difficult to achieve compactness when the image sensor is large. In the optical system of Patent Document 2, the spacing between the main variable magnification groups can be changed during zooming, or the number of lenses in the main variable magnification groups can be increased to achieve high image quality, but it is difficult to achieve a large aperture. In the optical system of Patent Document 3, the configuration of each lens group is optimized to achieve both weight reduction and suppression of chromatic aberration, but it is difficult to achieve compactness when the aperture is large.
• An object of the present invention is to provide a zoom lens which is small in size and has a large aperture, yet provides high optical performance .

Example 1

• Focal length: 409.335-582.738
• F-number: 2.880-4.100
• Half angle of view: 3.025-2.126
• Image height: 21.635
• Total length: 475.002
• Back focus: 39.500

Example 2

• Focal length: 306.239-582.535
• F value: 2.900-4.600
• Half angle of view: 4.041-2.127
• Image height: 21.635
• Total length: 475.001
• Back focal length: 41.785

Example 3

• Focal length: 71.997-291.389
• F-number: 4.120
• Half angle of view: 16.725-4.246
• Image height: 21.635
• Total length: 276.801-332.801
• Back Focus: 39.493-64.844

Example 6

• Focal length: 101.052-291.652
• F-number: 4.120
• Half angle of view: 12.084-4.242
• Image height: 21.635
• Total length: 279.187-308.962
• Back Focus: 39.496-52.523

via asobinet