A direct comparison of Canon's EF 70-200mm f/2.8L IS III USM lens (top) and its RF counterpart, the RF 70-200mm F2.8L IS USM (below). Thanks to the technical advances delivered by the RF mount, the developers of the RF lens were able to incorporate innovative technologies and cutting-edge design to ensure it is not just an RF-mount equivalent of the EF lens but a shorter, lighter, super-compact high-speed telephoto lens for a new generation of photography.
Canon's innovative RF lens mount debuted in September 2018 in the EOS R, the first of Canon's mirrorless EOS R System cameras. Coming just over 30 years after Canon's acclaimed EF mount was introduced, the RF mount was designed to enable a new generation of optical technology and creative possibilities.
All EOS R System cameras have the same RF mount whether the sensor in the camera is APS-C (as in the EOS R7 and EOS R10) or full-frame (as in other models). This means that all RF and RF-S lenses can be used on all EOS R System cameras, although the field of view of any given lens will be different on an APS-C camera from a full-frame camera, because of the APS-C sensor's "crop factor".
Here we look at some key aspects of the RF mount's design and the technical advances it has made possible.