Canon Patent: Focal Reducer For Mirrorless Camera With APS-C Sensor

Canon Patent

Well that’s a heck of a Canon patent application. A focal reducer that gives some exciting focal length and apertures on APS-C cameras

Spotted by Hi Lows Note, Canon patent application 2021-167921 (Japan) discusses optical formulas for a focal reducer that could transform a 50mm f/1.4 lens for full-frame cameras into a 33mm f/0.94 lens for APS-C sensor cameras. Not bad, eh? Hopefully Canon will release this thing for the EOS M system.


Master lens

  • Focal length (mm): 51.46
  • F number: 1.45
  • Half angle of view (degree): 22.80
  • Image height (mm): 21.64
  • Lens length (mm): 94.41
  • Back focus (mm): 39.81

With embodiment 4

  • Focal length (mm): 33.45
  • F number: 0.94
  • Half angle of view (degree): 22.42
  • Image height (mm): 13.80
  • Lens length (mm): 91.91
  • Back focus (mm): 9.73

Canon Patent: TS-E Macro Lens (might be the TS-E 90mm F2.8L Macro)

Canon Patent

A new Canon patent was spotted by asobinet.com. It’s for a tilt-shift lens and it might apply to an already released Canon lens.

Canon patent application 2021-167982 (Japan) discusses optical formulas for a tilt shift macro lens. The patent literature hints at an already released lens, the Canon TS-E 90mm f/2.8L Macro. From the patent literature:

PROBLEM TO BE SOLVED: To obtain an imaging optical system which has less aberration fluctuation during focusing from infinity to a short distance, has high optical performance over the entire focus range, and can easily secure a sufficient amount of peripheral light.

In recent years, an imaging optical system used in an imaging device such as an interchangeable lens still camera has a large aperture ratio, little aberration fluctuation during focusing from infinity to a short distance, and has high optical performance over the entire focus range. Is required.

The double-Gauss type imaging optical system is characterized in that it is easy to make a large-diameter ratio and the aberration fluctuation with respect to the fluctuation of the object distance is relatively small. However, in a double Gauss type imaging optical system, if the entire system is moved during focusing from infinity to a short distance, the amount of movement of the pupil increases. As a result, when trying to secure the peripheral illumination over the entire focus range, the effective diameter of the lens increases and the entire system becomes large.

In order to have a large aperture ratio, high optical performance when focusing from infinity to a short distance, and to obtain a sufficient amount of peripheral light, it is important to appropriately set the lens configuration, the material used for each lens, and the like. Will become.

Thepresent invention is an imaging optical system having little aberration fluctuation due to focusing from infinity to a short distance, having high optical performance over the entire focus range, and easily securing a sufficient amount of peripheral light, and an imaging apparatus having the same. The purpose is to provide.

  • Focal length: 90.00
  • F value: 2.91
  • Image height: 34.00
  • Overall length: 132.06
  • Shooting magnification: 0.5

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

Canon Patent: Yet Another Take On The Vlogging Concept

Canon Patent

Not the first Canon patent regarding a video camera you might hold with one hand. Typical use case for run & gun vlogging.

Canon patent application 2021-165785 (Japan) discusses methods and technologies for such a handheld vlogging device. From the patent literature:

[Problem] To perform various operations by one hand.

[Means for solving] A display part 303 is provided on the fixing part 30. The touch operation member 301 c is capable of performing at least an operation of the display unit 303 and is provided so as to be able to be pressed. The touch operation member 301 c can reciprocate in parallel with the push-in direction (Z-axis direction) and can reciprocate in a 1 predetermined direction (Y-axis direction ; C direction) substantially orthogonal to the push-in direction.

More detailed:

[Detailed description of the invention]
The present invention relates to an imaging device having a push-in operation portion which can be pushed in, and a photographing lens.

[Background of the Invention]In recent years, there has been a demand for moving image taking in a free posture and moving image taking from various angles in various situations. In the imaging apparatus disclosed in Patent Document 1, while the lens unit is rotated about one axis relative to the main body, the display unit can be reversed according to the direction of the lens unit while switching the imaging direction. This imaging apparatus is capable of switching between the self-photographing direction and the other-photographing direction by rotating the lens unit, and corresponds to various photographing styles.

Drawing from the patent literature

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

[source JPO]

Canon Patent: RF 28-70mm f/2.8L That Does Not Extend, Inner Focusing

Canon Patent

Here is a very interesting Canon patent application, once more for an RF mount lens. An RF 28-70mm f/2.8L with inner focusing and that does not extend might be in the works.

The Canon patent application spotted by asobinet.com (they did not disclose the patent number), discusses optical formulas for a RF 28-70mm f/2.8L lens. The interesting part, if I got it right from the machine translated Japanese text, is that the lens not only does all the focusing but also employs a design that is usually found on wide-angle lenses.

It sounds like a patent for a small and lightweight standard zoom. The characteristic of this optical system is that the total length is the longest at the wide-angle end and the total length becomes shorter toward the telephoto end. This is a common optical system for wide-angle lenses, but I don’t see this type of lens with standard zoom lenses, especially with large-aperture zoom lenses. If it is really put into practical use, it will be a very portable lens.

Did I get it right? The lens is indeed described to be shorter at the telephoto end (emphasis mine) in both embodiment:

  • Wide-angle intermediate telephoto
  • Focal length 28.84 36.81 67.90
  • F number 2.91 2.91 2.91
  • Half angle of view (°) 32.68 29.23 17.67
  • Image height 18.50 20.60 21.64
  • Lens total length 117.09 109.31 101.58
  • BF 9.99 13.47 21.59
  • Focal length 28.84 37.17 67.90
  • F number 2.91 2.91 2.91
  • Half angle of view (°) 32.65 28.90 17.67
  • Image height 21.64 21.64 21.64
  • Lens total length 132.62 122.81 111.18
  • BF 21.92 26.79 39.84

Moreover, the lens uses a floating focus structure to achieve autofocus. That means it might have very fast and and highly responsive AF. The patent literature is very clear in what should be achieved:

PROBLEM TO BE SOLVED: To provide a zoom lens having a short overall lens length, being compact and lightweight, and having high optical performance.

All comments welcome.

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

Canon Patent: RF 180mm f/3.5 Macro And RF 200mm f/4 Macro

Canon Patent

And here is a new Canon patent application and as most of them are, this one too is for RF-mount lenses.

asobinet.com spotted Canon patent application 2021-152568 (Japan). The patent application discusses optical formulas for both RF 180mm f/3.5 Macro and RF 200mm f/4 Macro lenses. The former lens might replace the EF 180mm F3.5L Macro USM, a lens that has already been discontinued.

PROBLEM TO BE SOLVED: To provide an optical system which is suitable for a macro lens and can suppress aberration fluctuation.

The optical system of each embodiment has an aperture aperture SP2 as a main focus aperture that determines (limits) the light beam of the open F number (Fno), and a positive refractive power arranged on the object side of the aperture aperture SP2. It has a front focus group LPF, a rear focus group LPR having a positive refractive power arranged on the image side of the aperture aperture SP2, and a negative refractive power arranged on the image side of the rear focus group LPR. It has a posterior group LN. The “group” as used herein means each group of lenses whose spacing changes during focusing.

Embodiment 1:

  • Focal length 171.00
  • F number 3.50
  • Half angle of view (°) 7.21
  • Image height 21.64
  • Overall length of optical system 194.49
  • BF 47.67
  • Magnification ∞ β = -1

Embodiment 2:

  • Focal length 174.43
  • F number 3.50
  • Half angle of view (°) 7.07
  • Image height 21.64
  • Overall length of optical system 189.49
  • BF 13.73
  • Magnification ∞ β = -1

Embodiment 3:

  • Focal length 140.00
  • F number 3.50
  • Half angle of view (°) 8.78
  • Image height 21.64
  • Overall length of optical system 177.49
  • BF 35.17
  • Magnification ∞ β = -1

Embodiment 4:

  • Focal length 194.00
  • F number 4.00
  • Half angle of view (°) 6.36
  • Image height 21.64
  • Overall length of optical system 202.49
  • BF 39.36
  • Magnification ∞ β = -1

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

Canon Patent: RF 16-30mm f/4-5.6 Lens For The EOR System

Canon Patent

Here is another Canon patent application for an RF-mount lens, as usual spotted by asobinet.com.

Canon patent application 2021-148949 (Japan) discusses optical formulas for what seems to be a RF 16-30mm f/4-5.6 lens for the EOS R full frame mirrorless system. From the patent literature:

PROBLEM TO BE SOLVED: To provide a small and wide angle-of-view zoom lens having high optical performance in the entire zoom range, and an image pickup device and an image pickup system having the same.

[…] In recent years, a zoom lens used in an imaging device is required to have high optical performance in the entire zoom range, to be compact and to have a wide angle of view, as the imaging device becomes more sophisticated. As a zoom lens that is small and relatively easy to widen, a negative lead type zoom lens in which a lens group having a negative refractive power precedes (is located closest to the object side) is known. As a negative lead type zoom lens, Patent Document 1 discloses a zoom lens composed of first to fourth lens groups having negative, positive, negative, and positive refractive powers arranged in order from the object side to the image side. ing. Further, Patent Document 2 discloses a zoom lens composed of first to fifth lens groups having negative, positive, positive, negative, and positive refractive powers arranged in order from the object side to the image side.

If it hits the market, this is going to be an affordable lens for the EOS R system, like the recently released RF 16mm f/2.8 STM pancake lens.

Embodiment 1:

  • Zoom ratio 1.79
  • Wide-angle intermediate telephoto
  • Focal length 16.48 22.05 29.50
  • F number 4.12 4.79 5.61
  • Half angle of view (degrees) 55.80 44.90 35.80
  • Image height 21.64 21.64 21.64
  • Lens total length 100.88 99.27 100.51
  • BF 14.00 16.25 19.80

Embodiment 2:

  • Zoom ratio 1.79
  • Wide-angle intermediate telephoto
  • Focal length 16.48 22.05 29.50
  • F number 4.12 4.12 4.12
  • Half angle of view (degrees) 55.20 45.00 36.20
  • Image height 21.64 21.64 21.64
  • Lens total length 110.07 105.92 108.00
  • BF 12.80 17.50 21.37

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