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.

This Metabones Speed Booster is a well made and quite brilliant adapter for those who’d like to mount Canon EF-mount lenses on Micro Four Thirds cameras. Not only does it allow control of the aperture in a Canon lens from a Micro Four Thirds camera, it supports image stabilisation where present and allows the camera to record EXIF data. With a magnification of 0.64x and advanced 6-element optical design users can transform Micro Four Thirds cameras into super-35 format 4K cine cameras while achieving extraordinary optical performance at apertures up to an incredible f/0.80. Autofocus is also supported, but we should point out it’s worth double-checking camera compatibility first.

The Metabones Canon EF lens to Micro Four Thirds T ULTRA 0.71x Speed Booster uses an advanced 5-element 4-group optical design incorporating ultra-high index tantalum-based optical glass.