Canon Patent: RF-S 14-30mm f/4-6.3 And RF 20-50mm f/4-5.6

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Here is a new Canon patent application, one for a RF-S and one for a RF lens.

Canon patent application 2024072459 (Japan, 5/28/2024) discusses optical formulas for two RF-mount lenses:

  • RF-S 14-30mm f/4-6.3 [for APS-C imaging sensors]
  • RF 20-50mm f/4-5.6

From the patent literature:

  • The present invention provides a zoom lens that is both compact and lightweight and has high image quality, has a short focal length at the wide-angle end, is easy to manufacture, is inexpensive, and allows high-speed zoom operations.
  • BACKGROUND ART
    Zoom lenses used in imaging devices are required to be small and lightweight, have various aberrations including chromatic aberration well corrected, and have high optical performance. Additionally, there is a demand for a zoom lens that has a short focal length at the wide-angle end, is easy to manufacture, and is inexpensive. Furthermore, there is a demand for a zoom lens that allows high-speed zoom operations.
  • In order to provide such a zoom lens, the arrangement of the aspherical lens is important. If an aspherical lens is placed in the second lens group, which is placed adjacent to the image side of the first lens group closest to the object and has a high axial ray height, the required precision of the aspherical lens will be high, making it difficult to manufacture. As the power increases, it becomes difficult to provide an inexpensive zoom lens. On the other hand, if an aspherical lens is not disposed in the second lens group, it will be difficult to suppress aberrations generated in the second lens group, making it difficult to achieve high image quality. Furthermore, in order to provide a zoom lens that can realize high-speed zoom operations, it is effective to fix the first lens group with a large lens diameter and move only the lens group with a small lens diameter. However, by fixing the first lens group closest to the object, aberration correction deteriorates and it becomes difficult to achieve high image quality.
  • Patent Document 1 describes a compact and lightweight zoom lens that includes a first lens group with negative refractive power, a second lens group with positive refractive power, and a second lens group with negative refractive power, which are arranged in order from the object side. A zoom lens has been proposed that includes a third lens group and a fourth lens group with positive refractive power. The first lens group is fixed relative to the image plane during zooming.
  • The present invention provides a zoom lens that is both compact and lightweight and has high image quality, has a short focal length at the wide-angle end, is easy and inexpensive to manufacture, and allows high-speed zoom operations.

Example 1

  • Focal length: 14.40-29.10
  • F value: 4.10-6.40
  • Half angle of view: 43.4-25.1
  • Total length: 75.06
  • Back focus: 11.78

Example 3

  • Focal length: 12.40-29.10
  • F value: 4.10-6.40
  • Half angle of view: 47.9-25.2
  • Total length: 82.67-82.67
  • Back focus: 11.71

Example 3

  • Focal length: 20.60-48.50
  • F value: 4.10-5.88
  • Half angle of view: 46.4-24.2
  • Total length: 106.52-106.52
  • Back focus: 19.41

More Canon patents are listed here.

[via asobinet]

Canon Announced New Flex Zoom Lens Series For Cinema With T2.4 Aperture

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Canon announced the new Flex Zoom Cinema lens series: Canon CN-E 20-50mm T2.4 LF and CN-E 45-135mm T2.4 L F/FP lenses. Preorders start at $21,999.

Canon press release:

Canon Announces New Flex Zoom Lens Series of EF Cinema Lenses with Wide T2.4 Aperture Designed for Full-Frame Cameras

MELVILLE, NY, April 12, 2022 – Canon U.S.A., Inc., a leader in digital imaging solutions, announced today the launch of a new series of lenses for the company’s EF Cinema Lens lineup — the Flex Zoom Lens series of lenses, which were developed to create cinema-style productions with greater workflow efficiency. The first lenses in the series are the CN-E20-50mm T2.4 L F/FP wide-angle zoom lens and the CN-E45-135mm T2.4 L F/FP telephoto zoom lens.

Designed in the pursuit of cinematic beauty, the new large-aperture lenses feature both high-level optical design and performance while maintaining the style and ease-of-use of Canon’s EF Cinema lens series. With the introduction of the zoom lenses featuring focal length ranges of 20-50mm for wide-angle and 45-135mm for telephoto, Canon now offers zoom lenses that cover the same range as its six existing prime (single focal length) lenses. The versatility of these new lenses supports efficient production workflows for a wide range of scenarios, including film, TV programs, commercials, and much more.

When paired with full-frame or large-format cameras, these lenses fully leverage the cameras’ signature shallow depth-of-field look and provide smooth and natural background blur, helping to produce powerful storytelling imagery. The lenses also maintain a bright T2.4 aperture1 across their entire zoom ranges allowing for image capture in both natural light and darker environments. This feature helps to reduce the need for intricate lighting setups, enabling more efficient and cost-effective video production workflows.

Engineered with an optical configuration that creates the optimal placement of lens elements, including a large-aperture aspherical lens and an anomalous dispersion glass lens, the CN-E20-50mm T2.4 L F/FP and the CN-E45-135mm T2.4 L F/FP lenses help reduce the potential for color smudging and chromatic aberrations. This enables them to maintain high optical performance from the center of the image to the periphery when paired with 8K cameras.

In addition to supporting EF-mount data transmission2, the new lenses are also compatible with /i Technology3 from Cooke Optics. With this capability, recording metadata such as focus, zoom, aperture, and lens model can be transmitted via the lens mount for visualization on the camera itself. This additional information helps to contribute to more efficient workflows not only during on-location recording, but also during post-production and editing.

Pricing and Availability
The Canon CN-E20-50mm T2.4 L F/FP wide-angle zoom lens and Canon CN-E45-135mm T2.4 L F/FP telephoto zoom lens are scheduled to be available in early June 2022 and early September 2022 for an estimated retail price of $21,999.00.*

Canon will showcase its latest digital imaging solutions and products, including the new Flex Zoom Lens series of lenses, at the NAB Show 2022 (Booth #C4432) in Las Vegas, April 24th-27th. For more information about the new lenses and Canon’s presence at the show please visit usa.canon.com.