The Canon EF Lens to Sony E-Mount Camera Lens Mount Adapter Mark IV from Metabones attaches a Canon EF lens to a Sony E-mount mirrorless camera. It is referred to as a “Smart Adapter” because it retains electronic communication between the camera and lens and therefore provides automatic aperture control, EXIF data, image stabilization and autofocus. The adapter is powered by the camera body, so no external power source is required. The Mark IV provides the same functions as the Mark III but provides optimized performance and an improved internal structure.
The Smart Adapter IV offers two distinct operation modes: Green and Advanced modes. Each mode supports a different set of features and is selected when you mount the lens. Green mode is the default mode and it is designed to conserve battery power by limiting aperture diaphragm movements and image stabilization. Certain other functions are not available in Green Mode including Auto-Magnify MF Assist and DOF preview.
The adapter’s tripod foot is detachable using an Allen wrench and compatible with Arca Swiss, Markins, Photo Clam ball heads.
Only Canon-branded lenses introduced in or after 2006 are officially supported. Autofocus speed is very slow and inadequate for most moving subjects. Autofocus may be disabled for older Canon lenses and most third-party lenses, including most Sigma, Tamron and Tokina lenses and all Contax N lenses modified by Conurus. This Smart Adapter is also compatible with fully manual lenses which have no electrical contacts. For a list of reported compatibility with specific lenses please see the Metabones website.