By site editor Dan Chung:
Metabones have finally released what has to be the most eagerly awaited lens adapter of recent times. The new Canon EF to Micro 4/3 active adapter has a 0.71x magnification factor, allows full control of iris electronically from the camera body and increases maximum aperture by one stop. Like the NEX version of the adapter there is a basic AF function but it is not as quick as a native m4/3 lens. Image stabilisation is supported which makes this adapter a very usable option for run and gun shooting. The adapter is available to purchase now for $599 from the Metabones website. For more details about the convertor head over to EOSHD.com.
Here are the details from Metabones:
Increase maximum aperture by 1 stop.
Makes lens 0.71x wider.
Build-in electronics to control lens aperture.
The lens aperture is set by the controls on the camera body.
Powered by camera body. no external power source required. (also accept 3rd party external power supply via MicroUSB socket)
High performance 32-bit processor and efficient switched-mode power supply.
The tripod foot is detachable and compatible with Arca Swiss, Markins and Photo Clam ball heads.
Optics designed by Caldwell Photographic in the USA (patent pending)