I upgraded my camera to the Canon EOS R5 last year and have since been shooting with my adapter ring and the EF lenses. If this sounds like jargon to you: let me catch you up to speed. Canon launched its first mirrorless camera in 2018, and the mount on the mirrorless cameras is different than the ones of the previous DSLRs. As a workaround, you can use an adapter ring to shoot with your older EF lenses on the new mirrorless cameras.