Here is a new Canon patent. One that will for sure start some bs rumors ;-)

This Canon patent application discusses optical formulas and methods for two lenses with diffractive optical elements:

• 400mm F4 TC DO
• 600mm F4 TC DO

From the patent literature:

• To provide an optical system having a short overall length and in which a magnification conversion optical group can be inserted and removed.
• Description of the Related Art: One method for changing the focal length of an optical system used in imaging is to insert a magnification conversion optical group such as an extender into the optical path. As an optical system in which the overall length (the distance from the optical surface closest to the object to the image plane) does not change by inserting or removing the magnification conversion optical group, Patent Document 1 discloses an optical system in which a magnification conversion group can be inserted or removed at a position where an axial light beam between an aperture stop and an image plane converges.
• However, providing a space between the aperture stop and the image plane to insert a magnification conversion optical group as in Patent Document 1 increases the overall length of the original optical system. Also, inserting a magnification conversion optical group in a narrow space may increase various aberrations in the optical system.
• The present invention provides an optical system in which a magnification conversion optical group can be inserted or removed, yet which has a short overall length and provides good optical performance.
• In each cross -sectional view, O represents the optical axis, IP represents the image plane, and G represents a glass block such as a quartz low-pass filter or an infrared cut filter. In Examples 1 and 2, Ldoe represents a diffractive optical element , and asph represents an aspheric surface. In both Examples 1 and 2, the diffractive surface of the diffractive optical element Ldoe is provided on the cemented surface of the second cemented lens counting from the object side. The aspheric surface asph is provided on the object-side optical surface of the positive lens closest to the object side.

Example 1

• Focal length: 392.58
• F-number: 4.12
• Half angle of view: 3.45
• Image height: 21.64
• Total length: 280.33
• Back Focus: 36.01

Example 2 (Example 1 with teleconverter inserted)

• Focal length: 549.72
• F-number: 5.77
• Half angle of view: 2.25
• Image height: 21.64
• Total length: 280.33
• Back Focus: 36.00

Example 3

• Focal length: 585.00
• F-number: 4.12
• Half angle of view: 2.12
• Image height: 21.64
• Total length: 467.45
• Back Focus: 55.5

Example 4 (Example 3 with teleconverter inserted)

• Focal length: 819.18
• F-number: 5.77
• Half angle of view: 1.51
• Image height: 21.64
• Total length: 467.45
• Back Focus: 55.50

More Canon patents are listed here.

[via asobinet]

Here is a lens review from our favourite reviewer. The awesome Sigma 10-18mm F2.8 DN for RF mounts gets under scrutiny.

At a glance:

• APS-C Format | f/2.8 to f/22
• 16-29mm (Full-Frame Equivalent)
• Ultra Wide-Angle Zoom
• Fast Internal Focus System
• Rounded 7-Blade Diaphragm
• Dust & Splash-Resistant Design

Dustin Abbott posted his exhaustive and full-fledged Sigma 10-18mm F2.8 DN Review. I can’t stress enough how good Mr. Abbott’s reviews are, and I recommend you have a look at it in case you’re interested in the Sigma 10-18mm F2.8 DN. The review comes with sample images, test charts, ISO comparison, and everything you might expect from a professional review. From the conclusion:

Autofocus was fantastic, image quality looks great, and the lens remains very impressive despite its small size. It’s a great match for smaller APS-C bodies in size, and the performance is strong enough to delight owners.

There really isn’t much in terms of competition, so it’s an easy lens to recommend on RF. It is actually the premium option, and while it is isn’t cheap at $659 USD, neither is it ridiculously expensive.

[…] the Sigma 10-18mm 2.8 DN is what I would be buying if I were in the market right now.

Pros:

• Fantastic job porting to Canon
• Extremely compact and lightweight
• Nicely made with a weather sealing gasket
• Useful focal range with constant F2.8 aperture
• Great autofocus performance
• Good video AF performance
• Almost non-existent focus breathing
• Good sharpness across zoom range
• Nice colors
• Good flare resistance
• Nicer build and handling than RF lenses

Cons:

• No optical stabilizer
• Fairly strong and complex barrel distortion at 10mm
• Twice as expensive as Canon’s own offering

If you prefer watching a gear review, here you are.

Sigma 10-18mm F2.8 DN: [shoplist 72516]

[via Dustin Abbott]

Here is a set of alleged Canon EOS R6 Mark III specifications as they have been leaked on Weibo.

The Canon EOS R6 Mark III might be the Canon gear registered as DS126941 at some registration authority. Here are the specifications:

• Dual-band WIFI
• 24-megapixel LC1720 sensor.
• DIGIC Accelerator accelerated processor, up to 8.5-stop image stabilization.
• Same autofocus system as EOS R5 II.
• 14-bit 30fps RAW electronic shutter continuous shooting, reading speed 1/180s.
• In-camera neural network noise reduction and high-resolution magnification.
• Supports XF-AVC S and XF-HEVC S recording of C4K/120p (S35) and 6K oversampled C4K.
• Supports 6K30p and 4K60p (S35) Cinema RAW Light recording.

Here is the image with the specifications as it leaked on Weibo.

Take it with a grain of salt, although the Weibo user who leaked the set of specs has been right in the past.

All Canon rumors are listed here. Stay tuned…

Only for today (10/14/2024) B&H Photo has an excellent deal on the Tokina atx-i 11-16mm f/2.8 CF Lens for Canon EF mounts (you can use it on your RF mount camera with the adapter.

At a glance:

• EF-Mount Lens/APS-C Format
• 17.6-25.6mm (35mm Equivalent)
• Aperture Range: f/2.8 to f/22
• Two Aspherical Elements
• Two SD Low Dispersion Elements
• Multi-Coated Elements
• One-Touch Focus Clutch Mechanism
• Internal Focusing Design
• 9-Blade Diaphragm

Get the Tokina atx-i 11-16mm f/2.8 CF for EF mounts on sale at $279. Compare at $499.

More selected deals:

• Get Excire Foto (AI powered photo managment) with 15% discount by using code “canonwatch” at checkout
• USA: Canon USA | B&H Photo | Adorama | Amazon US
• Germany: Amazon Germany
• Refurbished lenses and DSLRs at Canon Store (best deals might be found here)

Here is a new Canon patent, and it appear it is referring to the recently released RF 28-70mm f/2.8 IS STM lens.

Canon patent 2024140521 (Japan, published 10/10/2024) discusses optical formulas for a 28-70mm f/2.8 IS STM lens for the RF mount.

From the patent literature:

• The present invention provides a zoom lens that has high optical performance, a high zoom ratio, and is compact.
• 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 listed here.

Here is something cool for the tech nerds out there: A full teardown and disassembly of the Canon EOS R5 Mark II by Kolari Vision.

Canon EOS R5 Mark II at a glance:

• 45MP Full-Frame Stacked BSI CMOS Sensor
• DIGIC Accelerator Processing
• Dual Pixel Intelligent AF, Eye Control
• 8K 60 Raw/4K 60 SRAW/4K 120 10-Bit Video
• Up to 30 fps, Pre-Continuous Shoot Mode
• 5.76m-Dot EVF with OVF Sim. View Assist
• 3.2″ Vari-Angle Touchscreen LCD
• In-Camera Upscaling to 179MP
• CFexpress & SD UHS-II Memory Card Slots
• Wi-Fi 6E / Wi-Fi 6 Support

And here is the full teardown in 3 minutes:

Canon EOS R5 Mark II reviews are listed here.