Canon Patent: RF 28-70mm F2.8 Lens

28-70mm F2.8
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Canon patent application 2024104916 (Japan, published on August 6, 2024) discusses various optical formulas for a yet to be released RF lens: 28-70mm f2.8.

From the patent literature:

  • Description of the Related Art: In recent years, imaging optical systems used in imaging devices have been required to have high optical performance, a high zoom ratio, and a small size.
  • The zoom lens of Patent Document 1 has a lens group arranged in the order of positive, negative, positive, positive, negative, positive, from the object side to the image side. However, since the refractive power of the second lens group is strong, the chromatic aberration of magnification at the wide-angle end tends to become large, and the fluctuation of the curvature of field occurring during zooming tends to become large .
  • SUMMARY OF THE PRESENT EMBODIMENTS: An object of the present invention is to provide a zoom lens which has high optical performance, a high zoom ratio and is compact.

Example 1

  • Focal length: 28.80-67.90
  • F-number: 2.88-2.92
  • Half angle of view: 34.93-17.67
  • Image height: 21.64
  • Total length: 132.38-158.83
  • Back Focus: 15.39-34.87

More Canon patents are llisted here.

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Canon Patent: 28-70mm f/2.8 IS Lens

Canon Firmware Updates Viltrox Eos R7 Eos R10 Reuters Canon Cameras Europe Canon Eos R1 Eos R Rf 14-35mm Olympic Games Ef-mount Rudy Winston
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Here is a new Canon patent application. Does the patent refer to the Canon RF 24-70mm f/2.8L IS?

Canon patent application 2024078721 (Japan, published 6/11/2024) discusses optical formulas for a 28-70mm f/2.8 IS lens.

From the patent literature:

  • The present invention provides a compact zoom lens that has a high zoom ratio, good optical performance over the entire zoom range from the wide-angle end to the telephoto end, and has a large aperture and an image stabilization mechanism.
  • Background Technology
    In recent years, zoom lenses used in imaging devices such as digital cameras using solid-state imaging elements and silver halide film cameras are required to be small in size, have high optical performance, have a large aperture, and be equipped with an image stabilization mechanism (anti-vibration mechanism).
  • In order to achieve this, it is important to appropriately set the zoom type of the zoom lens and the lens group that moves during zooming.
  • The present invention provides a compact zoom lens that has a high zoom ratio and good optical performance over the entire zoom range from the wide-angle end to the telephoto end, has a large aperture, and has an image stabilization mechanism.

More Canon patents are listed here.

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

Canon Patent
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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:

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Canon Patent: Super Small 28-70mm f/2.8 & 28-60mm f/2.8 Lenses For RF Mount

Canon Patent
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A new and rather interesting Canon patent application. Very compact zoom lenses with large aperture.

Canon patent application 2022091621 (Japan) discusses optical formulas for two small and compact zoom lenses with large aperture:

  • 28-70mm f/2.8
  • 28-60mm f/2.8

From the patent literature:

PROBLEM TO BE SOLVED: To provide a zoom lens having a short total length and a small size but having high optical performance, and an image pickup apparatus having the same.

In recent years, with the increasing functionality of image pickup devices, there is a demand for a compact and lightweight zoom lens having a large aperture ratio. As a zoom lens that satisfies this requirement, a negative lead type zoom lens in which a lens group having a negative refractive power is arranged on the object side is known (see Patent Document 1 and Patent Document 2).

In the zoom lens of Patent Document 1, the refractive power of the first lens group is strengthened, and the movement locus of the first lens group during zooming becomes a substantially reciprocating locus, so that the total length of the zoom lens at the telephoto end can be increased. become longer. In addition, the back focus is long, and it is difficult to shorten the total length of the zoom lens. Further, the thickness of the first lens group becomes large due to the aberration correction in the first lens group, which is not preferable from the viewpoint of miniaturization and weight reduction.

In the zoom lens of Patent Document 2, the refractive power of the first lens group is strong in order to obtain a zoom magnification, and the configuration of the subsequent group is a four-group configuration up to the fourth lens group. If a larger aperture ratio is aimed at, it will not be possible to suppress various aberrations and zoom fluctuations of aberrations in the telephoto region, and it will be difficult to satisfy good optical performance over the entire zoom range.

An object of the present invention is to provide a zoom lens having a short overall length, a small size, and high optical performance, and an image pickup apparatus having the same.

In the zoom lens of each embodiment, in order to ensure good optical performance even at a close object distance, two or more lens groups among the lens groups arranged on the image side of the first lens group L1 are focused. It is preferable to have a so-called floating configuration in which the lens moves at the time.

Example 1

  • Focal length: 28.84-67.90
  • F value: 2.91
  • Half angle of view: 32.68-17.67
  • Image height: 18.50-21.64
  • Overall length: 138.40-105.42
  • Back focus: 10.97-21.12

Example 2

  • Focal length: 28.84-60
  • F value: 2.91
  • Half angle of view: 32.68-19.83
  • Image height: 18.50-21.64
  • Overall length: 132.38-106.85
  • Back focus: 13.47-23.82

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

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Canon RF 28-70mm f/2L Review (monster of a lens with monster performance)

Canon RF 28-70mm F/2L Review Rf Mount Canon Eos R
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Here is a new Canon RF 28-70mm f/2L review. The RF 28-70mm f/2 is one of Canon’s “boutique lenses” for the EOS R system.

At a glance:

  • RF-Mount Lens/Full-Frame Format
  • Aperture Range: f/2 to f/22
  • Ultra-Low Dispersion Elements
  • Ring-Type Ultrasonic Motor AF System
  • Customizable Control Ring
  • Rounded 9-Blade Diaphragm

Optical Limits posted their fuzll Canon RF 28-70mm f/2L review, and they underline the many virtues of this not-budget lens, of this outstanding lens. From their conclusion:

The Canon RF 28-70mm f/2 USM L is everything that you can expect from it – it is a monster of a lens with a monster performance. This is especially true for the broader center quality which is as good as on the best prime lenses. The outer image field is also superb in the lower zoom range. The corners soften a bit at 70mm but remain easily on a good level. That’s on a 45-megapixel sensor. On 20 to 30 megapixels, the lens is almost perfect. The native image distortions can be noticeable at 28mm but not an issue beyond. The native vignetting is quite high at f/2 but that’s no different from prime lenses. Auto-correction comes to the rescue in both cases, of course. Lateral CAs are absolutely negligible. The quality of the bokeh is good but there is a little room for improvement here. However, that’s complaining on a very high level really. The rather massive focus-breathing isn’t ideal for videos though.

The build quality is excellent which isn’t surprising given its professional target audience. The materials and assembly quality are top of the class. Weather-sealing is a natural feature at this price point anyway […] Read the review at Optical Limits…

More coverage of the outstanding Canon RF 28-70mm F/2L is listed here.

Canon RF 28-70mm F/2L: B&H Photo, Amazon USA, Amazon Canada, Canon Canada, Canon USA

Besides the review featured here, below you can watch a short overview of this amazing piece of glass.

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A Pro Photographer Changed Her Mind About The Canon RF 28-70mm f/2L

Canon RF 28-70mm F/2L Review Rf Mount Canon Eos R
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Sometimes you are mistaken, and if you can admit it, it’s a good sign. That’s what happened to a professional photographer with the Canon RF 28-70mm f/2L.

At a glance:

  • RF-Mount Lens/Full-Frame Format
  • Aperture Range: f/2 to f/22
  • Ultra-Low Dispersion Elements
  • Ring-Type Ultrasonic Motor AF System
  • Customizable Control Ring
  • Rounded 9-Blade Diaphragm

Katelyn James posted a video where she shares her experiences with the Canon RF 28-70mm f/2L lens:

A few months ago I made a review of the Canon RF 28-70 f/2.0 after using it for only one wedding day. Well 6 months later my opinion about this lens has changed… I LOVE IT more than I ever thought I would. It gives you all the advantages of shooting with prime lenses AND zoom lenses with almost zero compromise. I use it for 80%-90% of my images on the wedding day and want to share my experiences with this lens after using it non-stop for 6 months!

More coverage of the outstanding Canon RF 28-70mm F/2L is listed here.

Canon RF 28-70mm F/2L: B&H Photo, Amazon USA, Amazon Canada, Canon Canada, Canon USA

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