EF Lens Compatibility with Mount Adapter EF-EOS R 0.71xIn addition to RF lenses, the EOS C70 offers tremendous flexibility by also being compatible with Canon's broad line of award-winning EF lenses thanks to the new EF - RF optical adapter, Mount Adapter EF-EOS R 0.71x. This adapter converts light transmission from full-frame to Super 35mm image format. It extends the angle of view and optical sensitivity, while seamlessly integrating with the camera’s optical corrections. mount adapter.In addition to the flanges of the RF mount, four screws securely attach the adapter to the camera. Once mounted, the adapter maintains a similar angle of view of your full frame lenses on the Super 35mm sensor, while boosting the speed of the attached lens by an average of 1-stop. The adapter also carries all EF information through to the RF contacts, so on certain lenses, full DPAF and metadata will be available, working much as they do on a native EF mount.