Canon Patent: RF 70-300mm f/4.5-7.2 & RF 250-600mm f/6.3-11

Canon Patent
View Post

A new Canon patent, and once more more for RF mount lenses (what else?).

Canon patent application 2022178447 (Japan, published 12/2/2022) discusses optical formulas for two zoom lenses for the RF mount:

  • RF 70-300mm f/4.5-7.2
  • RF 250-600mm f/6.3-11

From the patent literature:

A compact and lightweight zoom lens that has high optical performance over the entire zoom range is provided.

Description of the Related Art

In recent years, zoom lenses used in image pickup apparatuses are required to have high optical performance and to be compact and lightweight.

As a zoom lens that meets these requirements, Patent Document 1 discloses a zoom lens having first to fourth lens groups with positive, negative, positive, and positive refractive powers arranged in order from the object side to the image side, A zoom lens is disclosed in which the spacing between adjacent lens groups changes during zooming.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a compact and lightweight zoom lens that has high optical performance over the entire zoom range, and an imaging apparatus having the zoom lens.

Example 1

  • Focal length: 103.01-387.98
  • F-value: 6.30-8.24
  • Half angle of view: 11.86-3.19
  • Image height: 21.64
  • Total length: 183.99-280.00
  • Back focus: 32.00-122.21

Example 2

  • Focal length: 103.01-347.20
  • F-value: 5.13-8.24
  • Half angle of view: 11.86-3.57
  • Image height: 21.64
  • Overall length: 198.72-267.94
  • Back focus: 32.86-136.99

Example 3

  • Focal length: 70.00-300.00
  • F-value: 4.40-7.20
  • Half angle of view: 17.17-4.12
  • Image height: 21.64
  • Total length: 165.01-231.87
  • Back focus: 27.80-102.92

Example 4

  • Focal length: 250.00-600.00
  • F-value: 6.24-11.33
  • Half angle of view: 4.95-2.07
  • Image height: 21.64
  • Overall length: 305.44-336.20
  • Back focus: 29.45-163.77

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

[via asobinet]

Canon Patent: RF 18-35mm f/1.8 DS & RF 120-300mm f/2.8 DS (Defocus Smoothing)

Defocus Smoothing
View Post

And here is another Canon patent application for two RF-mount lenses with Defocus Smoothing technology.

Canon patent application 2022175307 (Japan, published 11/25/2022) discusses optical formulas for two RF-mount lenses with Defocus Smoothing technology, RF 18-35mm f/1.8 DS & RF 120-300mm f/2.8 DS. No surprise Canon is porting this technology to the RF-mount. From the patent literature:

To provide a variable power optical system that obtains a good apodization effect over the entire zoom range and that has a small change in T number with variable power.

Description of the Related Art

Conventionally, in order to obtain an appropriate blurred image, there has been known an optical system equipped with a filter whose transmittance distribution changes, such as an apodization filter whose transmittance decreases as the distance from the optical axis increases. ing. Patent Literature 1 discloses an optical system in which apodization filters are arranged before and after the aperture of a single-focus lens.

However, since the optical system disclosed in Patent Document 1 is a single focus optical system, it is insufficient as a method for obtaining a sufficient apodization effect in each zoom state of the variable magnification optical system. In addition, as a specific requirement of a variable-magnification optical system, it is required that the change in brightness, that is, the T-number, is small when the magnification is varied, especially in video shooting.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a variable magnification optical system and an optical apparatus which have a good apodization effect over the entire zoom range and have a small change in T-number due to variable magnification.

Example 1

  • Focal length: 18.60-33.78
  • F-value: 1.80-1.86
  • Half angle of view: 37.69-23.05
  • Image height: 14.37
  • Overall length: 168.50
  • Back focus: 38.56-39.91

Example 2

  • Focal length: 18.50-34.00
  • F-value: 1.75-1.86
  • Half angle of view: 37.99-23.03
  • Image height: 14.45
  • Total length: 163.25-166.00
  • Back focus: 38.56-41.75

Example 3

  • Focal length: 37.00-68.00
  • F-value: 1.65-1.86
  • Half angle of view: 25.94-14.83
  • Image height: 18.00
  • Total length: 326.49-332.00
  • Back focus: 77.12-83.49

Example 4

  • Focal length: 51.50-97.00
  • F-value: 1.87
  • Half angle of view: 15.59-8.43
  • Image height: 14.37
  • Total length: 204.13-204.12
  • Back focus: 48.80-48.79

Example 5

  • Focal length: 123.60-290.82
  • F-value: 2.89
  • Half angle of view: 9.93-4.25
  • Image height: 21.64
  • Total length: 433.07-433.08
  • Back focus: 54.98-55.00

Canon Patent: RF 24-120mm f/2.8 IS & RF 85mm f/1.4 IS

Canon Patent
View Post

A new Canon patent application for a RF 24-120mm f/2.8 IS and RF 85mm f/1.4 IS lenses.

Canon patent application 2022175604 (Japan, published 11/25/2022) discusses optical formulas for two RF mount lenses, RF 24-120mm f/2.8 IS and RF 85mm f/1.4 IS. From the patent literature:

An object of the present invention is to reduce the size and weight of a movable group decentered with respect to an optical axis, while suppressing the occurrence of chromatic aberration due to the movable group.

Example 1

  • Focal Length: 24.72-116.36
  • F-value: 2.91
  • Half angle of view: 37.12-10.53
  • Image height: 21.64
  • Total length: 178.45-204.02
  • Back focus: 14.59

Example 2

  • Focal length: 82.47
  • F-value: 1.45
  • Half angle of view: 14.70
  • Image height: 21.64
  • Overall length: 126.52
  • Back focus: 13.50

Example 3

  • Focal length: 103.16-387.89
  • F-value: 4.64-7.30
  • Half angle of view: 11.84-3.19
  • Image height: 21.64
  • Total length: 176.10-288.59
  • Back focus: 15.98-63.01

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

[via asobinet.com]

Canon Patent: 35mm And 45mm f/2.8 For Full Frame, And 35mm f/2.8 For APS-C

Canon Patent
View Post

A new Canon patent for more RF mount lenses: 35mm and 45mm f/2.8 for full frame imaging sensors, and a 35mm f/2.8 for APS-C sensors.

Canon patent application P2022163979 (Japan, published 10/27/2022) discusses optical formulas for the following lenses for the RF mount:

  • 35mm f/2.8 (for full frame)
  • 45mm f/2.8 (for full frame)
  • 35mm f/2.8 (for APS-C)

From the patent literature:

A compact and lightweight optical system having high optical performance is provided by appropriately setting the refractive index and power arrangement of each lens.

Description of the Related Art

In recent years, imaging devices have been miniaturized, and the number of pixels of imaging elements used in the imaging devices has increased.

Description of the Related Art

As image pickup devices become smaller and have more pixels, optical systems used in image pickup apparatuses are required to have high optical performance, and to be compact and lightweight.

Example 1

  • Focal Length: 33.13
  • F-value: 2.91
  • Half angle of view: 33.15
  • Image height: 21.64
  • Overall length: 41.51
  • Back focus: 11.50

Example 2

  • Focal length: 34.76
  • F-value: 2.80
  • Half angle of view: 21.45
  • Image height: 13.66
  • Overall length: 40.98
  • Back focus: 13.10

Example 3 

  • Focal length: 46.55
  • F-value: 2.80
  • Half angle of view: 24.93
  • Image height: 21.64
  • Overall length: 53.50
  • Back focus: 14.80

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

[via asobinet]

Canon Patent: RF 28-70mm f/2.8 Lens That Retracts When Zooming

Canon Patent
View Post

Rather interesting Canon patent for a 28-70mm f/2.8 lens that becomes shorter when zoomed to the telephoto end, i.e. it retracts.

Canon patent 2022147945 (Japan, published 10/6/2022) discusses a rather interesting optical formula for a retracting 28-70mm f/2.8 zoom lens for the RF mount. A pretty unique optical design.

From the patent literature:

A zoom lens is provided which is compact and lightweight and capable of achieving high optical performance over the entire zoom range and all object distances.

Example 1

  • Focal length: 28.84-67.90
  • F-value: 2.91
  • Half angle of view: 32.65-17.67
  • Image height: 18.48-21.64
  • Overall length: 149.46-115.94
  • Back focus: 13.48-27.78

Example 2

  • Focal length: 24.72-67.90
  • F-value: 2.91
  • Half angle of view: 35.02-17.67
  • Image height: 17.32-21.64
  • Overall length: 150.00-130.39
  • Back focus: 9.87-27.17

Example 3

  • Focal length: 28.84-67.90
  • F-value: 2.91
  • Half angle of view: 34.77-17.67
  • Image height: 20.02-21.64
  • Overall length: 152.61-120.01
  • Back focus: 22.71-41.28

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

[via asobinet]

Canon Patent: 300mm f/2.8, 400mm f/2.8 And 600mm f/4 With Built-in Teleconverter

Canon Patent
View Post

A new Canon patent for telephoto lenses with built-in teleconverter. For what mount? RF mount.

Canon patent 2022142979 (Japan, published 10/3/2022) discusses optical formulas for three telephoto lenses with built-in teleconverter. The lenses are 300mm f/2.8, 400mm f/2.8 and 600mm f/2.8. From the patent literature (machine translated):

An object of the present invention is to provide an optical system having a variable power optical system that is inserted into and removed from a main optical system, and to achieve good optical performance while reducing the weight of the entire system.

Description of the Related Art

As a method for changing the focal length of an optical system used in an imaging apparatus, there is a converter method that changes the focal length of the entire system by inserting a variable magnification optical system (extender) in the optical path.

When adopting a system incorporating a variable magnification optical system, in order to achieve good optical performance while reducing the weight of the entire system including the variable magnification optical system, the insertion position of the variable magnification optical system must be appropriately selected. It is important not only to do so, but also to properly configure the main optical system. The invention disclosed in Patent Document 1 has room for improvement from the viewpoint of achieving both weight reduction and optical performance.

Summary of the invention

It is an object of the present invention to achieve good optical performance while reducing the weight of the entire system in an optical system having a variable magnification optical system that is inserted into and removed from a main optical system.

Example 1 ML

  • Focal length: 389.00
  • F-value: 2.91
  • Half angle of view: 3.18
  • Image height: 21.64
  • Total length: 406.00
  • Back focus: 53.83

Example 1 with teleconverter

  • Focal length: 544.00
  • F-value: 4.19
  • Half angle of view: 2.28
  • Image height: 21.64
  • Overall length: 406.01
  • Back focus: 53.83

Example 2 ML

  • Focal length: 582.00
  • F-value: 4.12
  • Half angle of view: 2.13
  • Image height: 21.64
  • Overall length: 486.10
  • Back focus: 81.91

Example 2 with teleconverter

  • Focal length: 814.80
  • F-value: 5.88
  • Half angle of view: 1.52
  • Image height: 21.64
  • Overall length: 486.10
  • Back focus: 81.91

More Canon patents are listed here.

[via asobinet]