Canon Patent: RF 70mm F2, RF 70mm F2.8, RF 75mm F2.4, and RF 85mm F2.8

Canon Patent
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A new Canon patent application for relatively fast prime lenses.

Canon patent application 2023149130 (Japan, published 10/12/2023) discusses optical formulas for prime lenses for the RF mount:

  • RF 70mm F2
  • RF 70mm F2.8
  • RF 75mm F2.4
  • RF 85mm F2.8

From the patent literature:

  • The present invention provides an optical system that is small and lightweight, yet can satisfactorily correct various aberrations including chromatic aberration and obtain high optical performance, and an imaging device having the same.
  • BACKGROUND ART
    In recent years, there has been a strong demand for optical systems used in imaging devices to have a compact overall lens system and high optical performance including chromatic aberration correction.
  • Generally, in a telephoto type optical system, as the focal length becomes longer, the entire lens system becomes larger and its mass increases. In order to miniaturize the optical system with a telephoto power arrangement, it is effective to strengthen the positive refractive power on the object side and the negative refractive power on the image side, but it is effective to increase the positive refractive power on the object side and the negative refractive power on the image side. Challenges arise in balancing both work and life.
  • Furthermore, in an optical system compatible with a large image sensor, it is important to perform focusing quickly using a small and lightweight lens group, and with less burden on the driving device. In a telephoto optical system, in order to easily perform focusing and to reduce aberration fluctuations during focusing, it is important to appropriately set the lens configuration of each lens group.
  • Patent Document 1 discloses that a first lens group with positive refractive power, a second lens group with negative refractive power, and a third lens group are arranged in order from the object side to the image side. An optical system is disclosed in which the distance between matching lens groups is varied.
  • However, in the optical system described in Patent Document 1, the number of lenses constituting the optical system is large, and the optical system cannot be sufficiently miniaturized.
  • The present invention provides an optical system that is small and lightweight, yet can satisfactorily correct various aberrations including chromatic aberration and obtain high optical performance, and an imaging device having the same.

Example 1

  • Focal length: 70.00
  • F value: 2.06
  • Half angle of view: 17.17
  • Image height: 21.64
  • Total length: 78.88
  • Back focus: 16.48

Example 2

  • Focal length: 70.00
  • F value: 2.83
  • Half angle of view: 17.17
  • Image height: 21.64
  • Total length: 68.97
  • Back focus: 17.41

Example 3

  • Focal length: 85.00
  • F value: 2.83
  • Half angle of view: 14.28
  • Image height: 21.64
  • Total length: 83.01
  • Back focus: 17.55

Example 4

  • Focal length: 75.00
  • F value: 2.40
  • Half angle of view: 16.09
  • Image height: 21.64
  • Total length: 86.00
  • Back focus: 15.64

More Canon patents are listed here.

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Today Only: Sirui 75mm f/1.8 1.33x Anamorphic Lens (Canon EF-M) – $399 (reg. $899)

Sirui 75mm F/1.8
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Only for today (12/14/2022) B&H Photo has a solid $500 discount on the Sirui 75mm f/1.8 1.33x Anamorphic Lens for Canon EF-M.

At a glance:

  • 75mm Anamorphic Canon EF-M Mount Lens
  • f/1.8 Maximum Aperture, 13-Blade Iris
  • Robust Aluminum Lens for APS-C Cameras
  • 2.4:1 Aspect Ratio; 13-Blade Iris
  • 1.33x Cinematic Anamorphic Squeeze
  • Schott Glass with Nano Coatings
  • Distance Markings in Feet and Meters
  • Horizontal Blue Streaks, Oval Bokeh
  • Manual Focus, M67 Filter Size

Get the Sirui 75mm f/1.8 1.33x Anamorphic Lens for Canon EF-M on sale at $399. Compare at $899. That’s a 56% discount!

More selected deals:

Click here to open the rest of the article

Today Only: Sirui 75mm f/1.8 1.33x Anamorphic Lens (Canon EF-M) – $499 (reg. $899)

Sirui 75mm F/1.8
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Only for today (9/12/2022) B&H Photo has a 55% discount on the Sirui 75mm f/1.8 1.33x Anamorphic Lens for Canon EF-M mount.

At a glance:

  • 75mm Anamorphic Canon EF-M Mount Lens
  • f/1.8 Maximum Aperture, 13-Blade Iris
  • Robust Aluminum Lens for APS-C Cameras
  • 2.4:1 Aspect Ratio; 13-Blade Iris
  • 1.33x Cinematic Anamorphic Squeeze
  • Schott Glass with Nano Coatings
  • Distance Markings in Feet and Meters
  • Horizontal Blue Streaks, Oval Bokeh
  • Manual Focus, M67 Filter Size

Get the Sirui 75mm f/1.8 1.33x Anamorphic Lens for Canon EF-M mount on sale at $499. Compare at $899.

More selected deals:

Click here to open the rest of the article

Meyer-Optik Gorlitz Primoplan 75mm f/1.9 II Lens Released

Primoplan 75mm F/1.9 II
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Born again Meyer-Optik Gorlitz released a new lens for various mount types, the Meyer-Optik Gorlitz Primoplan 75mm f/1.9 II.

The Meyer-Optik Gorlitz Primoplan 75mm f/1.9 II is available for the Canon EF mount (among others).

Mounts:Canon EF, Fuji X, Leica M, M42, MFT, Nikon F, Pentax K, Sony E
Aperture:f1.9 – f16
Focal length:75mm
Filter diameter:52mm
Minimum object distance:0,75 m
Rangefinder Coupling for Leica:no (focusing must be done via LiveView)

The Meyer-Optik Gorlitz Primoplan 75mm f/1.9 II sells at $999: B&H Photo.

Meyer-Optik Gorlitz Primoplan 75mm f/1.9 II Overview

Characterized by its speed and portrait-length field of view, the Primoplan 75mm f/1.9 II from Meyer-Optik Gorlitz is a sophisticated, yet simple prime for Canon EF-mount cameras. The bright f/1.9 maximum aperture pairs well with the short telephoto focal length to allow working with shallow depth of field and selective focusing techniques, and the fast aperture also benefits working in difficult lighting conditions. Its manual focus design further offers control when focusing down to 2.5′, and a 14-blade diaphragm contributes to a smooth bokeh quality. The five elements, four groups optical design makes use of Schott glass for a high degree of clarity, and an O’Hara Anti Reflex Coating has also been applied to limit flare and surface reflections for improved contrast and color accuracy. Additionally, the lens features an anodized aluminum housing that is durable, lightweight, and contributes to smooth, silent focusing performance.

  • Portrait-length prime is designed for full-frame Canon EF-mount cameras, however it can also be used on APS-C models where it will provide a 120mm equivalent focal length.
  • Fast f/1.9 maximum aperture allows for extensive control over depth of field, for working with selective focus techniques, and also benefits working in low-light conditions.
  • Inspired by the original Cooke triplet optical design, this lens uses a five elements, four groups layout in which the central dispersion element is surrounded by two groups of converging elements, and the rear element has a biconvex converging design to produce notable smoothness and clarity.
  • Schott glass is used for high clarity and contrast, and each of the elements feature an O’Hara Anti Reflex Coating to suppress lens flare and ghosting for color neutrality.
  • Manual focus design permits working with subjects as close as 2.5′ away.
  • Fourteen diaphragm blades contribute to a smooth bokeh quality.
  • Front 52mm filter thread is consistent throughout the Meyer-Optik Gorlitz version II lens series.

Here Are 5 Reasons To Get The Canon EOS R, And A First Look On The Kipon ELEGANT 75mm f/2.4 Lens

Canon Eos R Firmware Update
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Mattias Burling posted a short video where he explains why the Canon EOS R does well for his professional work. And he had a chance to use the new Kipon ELEGANT 75mm f/2.4 lens for EOS R mount.

He says:

[…] there is much more to like about the camera than I list in this video. For example in camera video color, highlight roll off, audio, etc, etc. Another negative is that its a bit too feature rich, capable and easy to use for it to challenge […] creatively on the streets. For recreational shooting I prefer something more limiting.

And I know there will be 4K crusaders commenting on me liking HD. […] I started shooting 4K Raw video before most you even left 720p. So I know all about it. The fact is that I have use had the HD from the EOS-R projected together with FS7 4K on huge screen and no one notices any difference. Law of diminishing return and the right tool for the job.