The Metabones Canon EF to Sony E Speed Booster allows you to mount any Canon EF-mount lens to compatible Sony NEX E-mount cameras and camcorders. Key features include:

High-Quality Optics. What separates this adapter from all the others is that it effectively increases your lens’s maximum aperture by 1 stop and widens your focal length by 0.71×. In other words, a Canon 50mm f/1.2 L would become a 35.5mm f/0.9 lens. With optics designed by Caldwell Photographic (the company behind the Coastal Optics 60mm Macro), modulation transfer function reportedly improves with the Speed Booster.

Electronic Communication. Like the other Metabones EF/NEX Adapters, this adapter provides electronic communication between the Sony camera and Canon lens. It allows full aperture control when shooting in A and M exposure modes, or lets the camera control aperture when shooting in P or S exposure modes. Not only do you have aperture control, but it’s also embedded in the EXIF data. The Metabones adapter also supports compatible lenses’ Image Stabilization functions, allowing you to shoot at slower shutter speeds and helping to eliminate camera shake.

Powered by the Camera Body. This adapter is powered by your camera body, so it doesn’t require any additional power source.

Durable Metal Construction. This adapter’s barrel and mounts are all constructed of metal. It offers a removable Arca-Swiss type plate for added lens support. Since the aperture blades change as you make adjustments, there’s a “wide-open” button which functions as the opposite of a depth-of-field preview button.

Limited Autofocus Support. This adapter supports autofocus, albeit with severe limitations, such as no continuous autofocus. At this time, autofocus is not reliable with Sony NEX Camcorders. It does work (slowly) with Sony NEX photo cameras equipped with newer Canon-brand (no third-party) lenses. Sony NEX cameras can’t display aperture values beyond f/1.0. If a f/1.2 Canon EF lens is used with the Speed Booster, the resulting aperture is f/0.9 but the camera body displays f/1.0.