The Canon Mount Adapter EF-EOS R is a lens mount adapter designed to connect Canon EF and EF-S DSLR lenses to Canon RF-mount mirrorless cameras. It enables photographers transitioning to the EOS R system to continue using existing EF lenses without changing optical performance.

The adapter maintains full electronic communication between the lens and camera, supporting autofocus, image stabilization, and aperture control. Its compact metal construction with dust- and water-resistant sealing makes it suitable for professional photography, hybrid video production, and everyday mirrorless workflows.