Canon Professional Service Center reports that:
If your Canon RF 800 f/11 lens suddenly and consistently fails to focus and takes consistently very blurry pictures, try resetting the camera as a first step toward fixing the problem.
The above happened to me. My R5 camera was still working fine with my 35mm macro lens but not with the 800mm f/11 lens so I sent the lens to Canon Professional Service Center only to be told that there is nothing wrong with the lens. I have now reset the camera as they suggested and it is still working properly with my 35mm Macro lens. I am eagerly awaiting the return of my 800mm f/11 lens and I shall return with the result.
If your Canon RF 800 f/11 lens suddenly and consistently fails to focus and takes consistently very blurry pictures, try resetting the camera as a first step toward fixing the problem.
The above happened to me. My R5 camera was still working fine with my 35mm macro lens but not with the 800mm f/11 lens so I sent the lens to Canon Professional Service Center only to be told that there is nothing wrong with the lens. I have now reset the camera as they suggested and it is still working properly with my 35mm Macro lens. I am eagerly awaiting the return of my 800mm f/11 lens and I shall return with the result.