Canon Patent: Compact APS-C Wide Primes — 10mm, 12mm, 18mm & 28mm F2.8

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Canon has filed a patent application (publication number P2026052804, published March 25, 2026, filed September 12, 2024) covering optical systems that look suspiciously like a lineup of compact APS-C prime lenses. The patent — titled simply "Optical System and Imaging Device" — presents multiple embodiments clustered around an F/2.8 aperture class, covering focal lengths from 10mm to 28mm.

Here's what the optical data tells us:

Embodiment 1 — ~12mm F2.8

  • Focal length: 12.38mm
  • F-number: 2.83
  • Half angle of view: 42.99°
  • Image height: 11.54mm
  • Total length: 63.50mm
  • Back focus: 12.00mm

Embodiment 3 — ~28mm F2.8

  • Focal length: 28.17mm
  • F-number: 2.83
  • Half angle of view: 24.14°
  • Image height: 12.63mm
  • Total length: 67.03mm
  • Back focus: 15.32mm

Embodiment 4 — ~10mm F2.8

  • Focal length: 10.02mm
  • F-number: 2.83
  • Half angle of view: 48.98°
  • Image height: 11.52mm
  • Total length: 65.00mm
  • Back focus: 12.00mm

Embodiment 7 — ~14mm F2.8

  • Focal length: 14.63mm
  • F-number: 2.83
  • Half angle of view: 39.45°
  • Image height: 12.04mm
  • Total length: 64.29mm
  • Back focus: 16.54mm

Embodiment 8 — ~18mm F2.8

  • Focal length: 18.13mm
  • F-number: 2.83
  • Half angle of view: 33.83°
  • Image height: 12.15mm
  • Total length: 70.71mm
  • Back focus: 12.17mm

What's Canon Up To?

A few things stand out immediately. All embodiments share a tight F/2.83 aperture — clearly a unified F2.8 optical design philosophy across the series. The total lengths are remarkably compact: sub-70mm for everything from 10mm to 28mm is impressive. These aren't the kind of chunky pro primes Canon builds for RF full-frame.

The image heights are the interesting wrinkle. At 11–12mm image height, these designs fall short of what you'd normally expect for APS-C (which typically needs ~14mm image height). Asobinet's own analysis notes this discrepancy, suggesting Canon may be designing these with some built-in cropping in mind — trading a bit of the corner image circle to correct residual distortion in-camera. This isn't unusual; several existing Canon lenses do exactly this.

The back focus situation: With back focus values of 12–15mm across the lineup, these are clearly designed for a short flange-to-sensor distance mount. That points firmly at EF-M or RF-S / EOS R APS-C territory. Canon's EF-M system is effectively on life support at this point, so RF-S is the logical destination — meaning these could be affordable compact primes for the EOS R50 / R10 / R100 crowd.

Does This Mean Anything?

As always with Canon patents: file with healthy skepticism. Canon patents prolifically, and the vast majority never leave the lab. That said, this is a coherent, well-structured lineup — five focal lengths with unified aperture and compact dimensions — which suggests someone at Canon was seriously thinking about a kit of compact APS-C primes. Whether that becomes RF-S 10mm F2.8, 12mm F2.8, 18mm F2.8, and 28mm F2.8 lenses is another question entirely.

What Canon has shown with the RF-S line so far is a willingness to offer affordable, small lenses for their crop-sensor mirrorless bodies. A set of fast-ish primes in this style would fill a real gap in the RF-S lineup, which currently leans heavily on zooms. Fingers crossed this one actually makes it to production.

Source: Asobinet (Japanese) — Patent P2026052804

Canon Patent: Fast Wide Primes — 14mm f/1.4, 18mm f/1.4, 35mm f/1.8 Optical Systems

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Canon is apparently not done dreaming about fast wide primes. A new patent application published March 12, 2026 (JP P2026043301, filed August 28, 2024) covers a family of large-aperture wide-angle optical systems — and the specs on paper are the kind of thing that makes lens nerds sit up straight.

The stated goal? “Provide an optical system with a large aperture ratio, high optical performance, and fast focusing capability.” Bold words. Let’s look at what they’re actually proposing.

The Patent: Five Optical Systems, One Ambitious Brief

The application includes at least five worked examples spanning a broad range of focal lengths:

ExampleFocal LengthF-valueHalf-angleImage HeightTotal LengthBack Focus
Ex. 114.42mmf/1.4652.34°18.68mm118.50mm14.00mm
Ex. 220.60mmf/1.4642.54°18.90mm117.50mm18.44mm
Ex. 324.72mmf/1.4637.40°18.90mm117.50mm15.00mm
Ex. 418.45mmf/1.4645.46°18.75mm121.17mm17.78mm
Ex. 734.00mmf/1.8530.41°19.96mm98.50mm14.00mm

In plain English: Canon is exploring 14mm f/1.4, 18mm f/1.4, 20mm f/1.4, 24mm f/1.4, and 35mm f/1.8 optical designs — all with large image circles consistent with full-frame sensors.

The Back Focus Situation (Here We Go Again)

Here’s where it gets interesting — and a little speculative. The RF mount has a flange focal distance of 20mm. Several of these designs have back focus values well below that threshold: 14mm (Ex. 1), 15mm (Ex. 3), 14mm (Ex. 7), and 17.78mm (Ex. 4). Only Example 2 at 18.44mm gets close.

Short back focus in a patent design doesn’t automatically disqualify RF compatibility — there are design tricks (rear floating elements, internal focusing groups) that can shift real-world performance away from the listed patent geometry. But it does raise the familiar question that haunts Canon patent watching: are these RF, EF, or something else entirely? Canon has filed similar wide-aperture designs in the past that turned out to be for cinema lenses or specialized applications rather than consumer RF glass.

That said, the image heights (18.68–19.96mm) are solidly full-frame territory, and the total lengths (98–121mm) are reasonable for fast prime construction.

What It Could Mean for Canon Shooters

Canon’s RF wide-prime lineup still has some gaps. The RF14-35mm f/4L IS USM covers the ultra-wide zoom territory, and the RF15-35mm f/2.8L handles the faster end — but dedicated fast wide primes like a 14mm f/1.4 or 20mm f/1.4 would be genuinely new territory for RF. Sony has the FE 14mm f/1.8 G Master and the FE 20mm f/1.8 G; Nikon has the Z 20mm f/1.8 S. Canon RF shooters interested in astrophotography, architecture, or environmental portraits at wide angles have been waiting.

A 35mm f/1.8 RF, meanwhile, would slot neatly between the existing RF35mm f/1.8 Macro IS STM (budget end) and the RF35mm f/1.4 L VCM (flagship). Whether Canon actually wants to fill that middle ground is another question.

The Standard Caveats Apply

Patents are not products. Canon files dozens of optical system patents that never see production glass. This one is interesting because it covers multiple related focal lengths in a single application, which sometimes signals more serious R&D intent — but it’s still early days. Filed in August 2024, published March 2026, and almost certainly years from a camera store near you, if it ever gets there at all.

Still: a 14mm f/1.4 RF would be something. We’ll be watching.

Source: とるなら (asobinet.com) — Patent JP P2026043301, published 2026-03-12, filed 2024-08-28.

Canon Patent: 28-45mm f/1.2 and 35-70mm f/1.4 Zoom Lenses With Reflective-Transmissive Elements

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Canon just dropped a new patent, and it’s making us raise an eyebrow. Published February 27, 2026 (filed August 2024), the patent describes zoom lenses with apertures ranging from f/1.2 to f/1.4 — using reflective-transmissive (mirror) elements to keep things compact.

The Patent Details

The filing (P2026033938) covers several implementations:

  • Example 2: 28-45mm f/1.2 — backfocus 0.40mm
  • Example 3: 28.5-45mm f/1.4 — backfocus 0.40mm
  • Example 5: 35-70mm f/1.4 — backfocus 0.70mm

Example 2

  • Focal length: 28.00-45.00
  • F-number: 1.20
  • Half angle of view: 37.26-25.33
  • Image height: 21.30
  • Total length: 222.37-171.73
  • Back focus: 0.40

Example 3

  • Focal length: 28.50-45.00
  • F-number: 1.40
  • Half angle of view: 35.22-25.68
  • Image height: 20.12-21.64
  • Total length: 189.76-137.77
  • Back focus: 0.40

Example 4

  • Focal length: 15.40-36.01
  • F-number: 1.42
  • Half angle of view: 36.86-20.54
  • Image height: 11.54-13.49
  • Total length: 165.18
  • Back focus: 0.40

Example 5

  • Focal length: 35.70-68.00
  • F-number: 1.40
  • Half angle of view: 28.55-17.65
  • Image height: 19.42-21.64
  • Total length: 227.59
  • Back focus: 0.70

That’s… extremely short backfocus. Like, “we’re not talking about RF mount” short.

Wait, What?

For context, RF-mount lenses need a backfocus of around 20mm+ to clear the mirror. These numbers — 0.40mm and 0.70mm — are barely enough to clear a sensor. This suggests the optical design is intended for:

  • Compact cameras — where the lens sits directly on or very close to the sensor
  • Surveillance cameras — where catching every photon matters more than shallow DoF
  • Cinema sensors — some have extremely short flange distances

Not interchangeable lenses. Canon confirmed this in the filing notes: “backfocus is extremely short so this is not intended for interchangeable lens systems.”

But Here’s The Fun Part

Canon previously filed similar patents for prime lenses using the same reflective-transmissive technology — a 24mm f/0.7 and a 12mm f/1.0. Those were weird enough. Now they’re applying the same trick to zooms, going even wider and faster. A 28-45mm f/1.2 zoom would be absolutely enormous if built with conventional optics. The mirror elements fold the light path, dramatically shrinking total length.

Our Take

Is this coming to an RF-mount lens? Almost certainly not. The backfocus is physically incompatible.

Could this be a hint at future compact camera ambitions? Maybe. The G7 X line is due for a replacement, and a 28-45mm f/1.2 equivalent in a pocketable body would be something to see.

Or maybe Canon just likes filing patents for lenses they’ll never build. We’ve seen stranger things.

Source: Asobinet

Sigma Patent: 70-200mm f/4 DG DN OS Lens For FF Mirrorless Cameras

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A Sigma patent application for a 70-200mm lens for full frame mirrorless cameras. Let’s hope for the EOS R system too.

Sigma patent application 2020-86133A discusses the optical formula for a 70-200mm DG DN OS lens , “OS” being Sigma’s denomination for in lens image stabilization.

  • Zoom ratio: 2.68
  • Focal length: 72.50 118.13 193.95 mm
  • F number: 4.00 3.99 4.00
  • Angle of view: 33.22 20.36 12.38
  • Image height: 21.63 21.63 21.63 mm
  • Lens length: 200.60 200.60 200.60 mm

Canon patent applications are listed here.

Canon Patent Application: IBIS and Lens IS Working Together

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Here is another Canon patent application dealing with how to make IBIS (In Body Image Stabilisation) and lens IS work together smoothly.

Canon patent application 2019-215426 (Japan) discusses the possibility of a change in the composition that occurs when IBIS and lens IS are working together. If both are working only while shooting, the resulting composition might be slightly shifted compared to what was seen in the viewfinder.

Although the camera in the image on top resembles more a DSLR than a MILC, we think this patent application too will find its way in a future EOS R camera body. We expect two new EOS R cameras in Q1 and Q2 2020, will this technology be already on board?

We have no doubts that Canon will feature IBIS on future cameras, given the remarkable collection of patent applications dealing with it and the fact that a Canon exec told the world about. And it’s very likely that the first Canon camera to feature it will be mirrorless.

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

Canon Patent For Various RF Mount Zoom Lenses

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Canon patent application US20190369372 discusses optical formulas for various zoom lenses for the Canon EOS R system.

Among the discussed optics in this Canon patent application is a 28-280mm f/2.8 lens. All lenses seem to be designed for the EOS R full frame mirrorless system.

A zoom lens includes, in order from an object side, a positive first unit, a negative second unit, a positive intermediate group consisting of one or two units and including a third unit located on a most object side, a negative unit, and a rear group consisting of one or two units including a positive unit located on a most object side. Conditional expressions are satisfied with respect to amounts of movement of the second and third units from a wide angle end to a telephoto end, a distance at the wide angle end from a most object side surface vertex in the first unit to a most object side surface vertex in the third unit, an Abbe number of a most object side lens in the first unit, a focal length of the second unit, and focal lengths at the wide angle end and at the telephoto end.

[…]

A zoom lens of the disclosure includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an intermediate lens group having a positive refractive power and including one or two lens units inclusive of a third lens unit located on an object side, a lens unit having a negative refractive power, and a rear lens group including one or two lens units inclusive of a lens unit which is located on the object side and has a positive refractive power, which are arranged in order from the object side to an image side. Here, an interval between every two adjacent lens units is configured to be variable for zooming. In the meantime, a total length of the zoom lens is reduced by keeping the first lens unit unmoved relative to an image plane while varying the intervals between the lens units during the zooming. The first lens unit includes three or more lenses and mainly corrects a spherical aberration and an axial chromatic aberration on a telephoto side. The second lens unit includes three or more lenses and mainly suppresses variations in curvature of field and in chromatic aberration of magnification during the zooming. In order to achieve correction of aberrations and reduction in size at the same time, it is preferable to form each of the first lens unit and the second lens unit by use of three or four lenses. 

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