That's what a Canon patent application seems to suggest, a 300mm f/2.3 mirror lens. Read…
Canon patent application 2019-113645 describes a design for a lens cap that might once for all solve the issue with lost lens caps.
The lens cap described in the Canon patent opens (and closes) without being removed form the lens. There is more: the lens cap is a lens cap when closed and becomes a lens hood when opened. Pretty smart.
The present invention works as a lens hood function at the time of shooting and as a lens protection function at the time of non-shooting, thus eliminating the need for lens cap attachment / removal and barrier opening / closing operations.
More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:
- 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