When Canon unveiled its first full-frame camera, the EOS R, in 2018, the company touted its new EOS RF lens mount. While it has the same 54-millimeter diameter as the DSLR EF mount, the RF mount’s flange distance is significantly shorter, shrinking from 44 millimeters to just 20. Canon promised that this would enable bold new lens designs, and the company’s latest lenses show that as well as any of Canon’s 40-plus RF lenses.
