At the time of testing this new Sigma lens, Canon is currently offering four APS-C format mirrorless EOS R system cameras, but only four dedicated APS-C format lenses to go with them. Naturally, you can use full-frame compatible ‘RF’ lenses on these cameras but, even so, all four of Canon’s ‘RF-S’ lenses are zooms with fairly slow aperture ratings, shrinking to f/6.3 or f/7.1 at the long end. With Canon keeping such tight control over its EOS R tech since the system was launched back in 2018, only ‘dumb lenses’ with no autofocus or electronic communication with the camera body were available until recently. But that’s changed with the launch of a new brace of Sigma lenses.
