The EOS R System, which uses the RF mount, began in 2018. Over 30 years since the launch of the EF mount and EOS System, it marks the start of a new Canon imaging system that is equipped for even greater flexibility and growth potential. With further expanding shooting scenarios as its aim, the EOS R System required a mount with new specifications that would ensure maximum growth potential and the optical design flexibility to realize ideal lenses. By making the development of lens groups the core of the system through the RF mount, the EOS R System looks ahead to becoming an image input system that will evolve long into the future.
The RF mount dramatically increases the flexibility of optical design and enables ideal lens development with a 54mm inner-diameter large diameter and short back focus. Loaded with potential, it allows maximum f/2 large-aperture standard zoom lenses not possible with earlier products. Another major feature of the EOS R System and RF mount is the new mount communication system. It greatly improves communication speed, instantly communicating large volumes of information with the camera: focus, zoom, aperture, degree of image stabilization, lens aberration, and data for digital lens optimizers (DLO). With these features, the system achieves outstanding image resolution with an open aperture, beautiful bokeh from its large aperture, fine aberration correction, and comfortable operability through a new control ring on the lenses.