This is a useful solution for anyone wishing to use Canon EF mount lenses on Sony’s full-frame mirrorless cameras without losing all-important lens functionality such as aperture control, autofocus or optical image stabilisation. Roughly the same size as a Canon EF 1.4x extender, it adds just 150g in weight to camera setups, has an on/off switch to control the camera’s in-body stabilisation and supports most autofocus functionality on Sony A7-series cameras, including real-time Eye AF. Users shouldn’t expect EF-mount autofocus lenses to focus as fast on a Sony camera as they do on a native Canon body. Generally speaking, autofocus response is adequate for subjects that don’t move quickly or are erratic in their behavior.
Adaptor with revolutionary optics to increase aperture and width of lens.
Sigma’s MC-11 mount converter is a solution to being able to use Canon and Sigma EF-mount lenses on Sony E-mount cameras. It’s well made as we’ve come to expect from the Japanese manufacturer and is relatively slim, adding just 2.5cm to the depth of the camera. Its key characteristic is the way it communicates the information that’s required between camera and lens to enable autofocus functionality and exposure control. It does have a few limitations though. It’s not weather sealed, its performance isn’t guaranteed for all adapted lenses and it works best with Sony E-mount cameras that feature phase detection autofocus.