The Canon RF lens mount is an interchangeable-
lens mount developed by
Canon for its
full-frame mirrorless interchangeable-lens camera
A mirrorless camera is a photo camera featuring a single, removable lens and a digital display.
The camera does not have a reflex mirror or optical viewfinder like a digital single-lens reflex (DSLR) camera, but may have an electroni ...
s, and featured first by the
EOS R, followed by the
EOS RP. The RF mount was announced in September 2018. In May 2022, Canon announced
APS-C
Advanced Photo System type-C (APS-C) is an image sensor format approximately equivalent in size to the Advanced Photo System film negative in its C ("Classic") format, of 25.1×16.7 mm, an aspect ratio of 3:2 and Ø 31.15 mm field ...
EOS R cameras (the EOS R10 and
EOS R7) and RF-S lenses designed for these cameras.
The RF mount allows for the use of Canon
EF and
EF-S
The Canon EF-S lens mount is a derivative of the EF lens mount created for a subset of Canon digital single-lens reflex cameras with APS-C sized image sensors. It was released in 2003. Cameras with the EF-S mount are backward compatible with the ...
mount lenses using one of three Canon-made
lens adapters. When an RF-S or EF-S lens is attached, however, the camera will only function as an
APS-C
Advanced Photo System type-C (APS-C) is an image sensor format approximately equivalent in size to the Advanced Photo System film negative in its C ("Classic") format, of 25.1×16.7 mm, an aspect ratio of 3:2 and Ø 31.15 mm field ...
camera, not a full-frame camera.
Details
Canon
full-frame cameras have used the
EF lens mount since 1987. In comparison with that mount, the RF mount's inner diameter is the same at 54 mm.
The RF mount's
flange focal distance at 20 mm is much shorter than that of the Canon EF and
EF-S
The Canon EF-S lens mount is a derivative of the EF lens mount created for a subset of Canon digital single-lens ref