A new Canon patent application for another RF mount lens. Canon patent application 2023018429 (Japan, published 2/8/2023) discusses optical formulas for an RF 100-300mm F2.8 x 1.4 extender lens.

From the patent literature:

A zoom lens having a large aperture and a long focal length is provided, in which the focal length range can be easily changed to the long focal length side by an extender, and good optical performance can be maintained even before and after the extender is inserted.

A known method is to change the focal length of the optical system by inserting an extender (magnification conversion group) separate from the main optical system.

However, since a large air gap is required to insert the extender into the optical path, if the position for inserting the extender is inappropriate, the size of the main optical system and the extender will increase. Also, in order to maintain good optical performance before and after inserting the extender, it is necessary to appropriately set the refractive powers of the lens groups before and after the extender.

In the present invention, by inserting an extender into the main optical system, the focal length range can be easily changed to the long focal length side. The purpose is to provide a long zoom lens.

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

• RF 16-28mm lens with either f/2.8, f/2.8-4, or f/4
• Automatic shutter silencing based on subject and distance
• A bunch of prime lenses for the RF mount
• An improved Electronic Viewfinder
• Patent application for RF 50mm F1.4 and an RF 35mm f/1.4 lenses
• A zoom lens that might be for an EOS R with APS-C sensor
• A smaller IBIS unit.
• A cooling adapter for the RF mount (R5 overheating?)
• A bunch of macro lenses for the RF mount.
• A 8mm f/4 circular fisheye lens for the Canon EOS R system
• A battery grip that works with differently siszed cameras
• A 100-400mm f/5.5-7.1 lens for APS-C cameras. EOS M or DSLR?
• RF 17-70mm lens for EOS R system
• IBIS coming to the EOS M and PowerShot lineup?
• Patent Application: mirrorless camera with large display and virtual control wheel
• Patent Application: IBIS and Lens IS Working Together
• Patent application for high speed mirror movement and control
• Patent application for an RF 14-28mm f/2 lens
• Patent application for an RF 50mm f/1.8 lens
• Patent application for a smart lens cap
• Patent application for celestial auto-focus
• Patent application describing a Pop-Up Flash With LED
• Patent application describing the optical formula for a RF 70-300mm F/4-5.6 IS lens for EOS R systems
• Patent application describing how to improve burst rate by compressing raw files
• Patent application describing a new way to review photos from a sequential shot
• Patent application that describes technology to improve wireless communication while reducing power consumption
• Patent application to spot and reduce moire artefacts in image data
• Patent application for weather sealed lens adapter
• Patent application for AI powered predictive camera control system
• Patent application for 18-55mm kit lens with LCD display
• Patent application to reduce noise in image files

[via Digicame-Info]