The Canon EF Lens to Micro Four Thirds Speed Booster from Metabones allows a full frame Canon EF lens to be mounted to a Micro Four Thirds mount camera and in doing so, increases the angle of view by 0.71x and increases the maximum aperture one f/stop.
When a lens intended for full frame sensors or 35mm film is mounted to a camera with a Micro Four Thirds sensor, it transmits a larger area of light than the smaller sensor was built to accept and therefore the effective angle of view of the lens increases. The Speed Booster condenses light from the lens and projects it onto the MFT sensor allowing it to utilize all of the lens′ light and effectively reduces the crop factor of an MFT camera from 2x to 1.07x, producing a full-frame angle of view with an MFT sensor. A corresponding increase in the maximum aperture of one f/stop makes the lens more effective in low-light situations and able to create a shallow depth of field.
Automatic exposure information is communicated by the speed booster and controlled from the camera body. No external power source is required as the speed booster is powered by the camera and houses a 32-bit processor. A power-conserving Green Mode is supported as well as an Advanced Mode which enables functions such as auto magnify focus assist and depth of focus preview. A wide-open button enables easier focusing and adjustments for infinity focus can be easily made if necessary.
Metabones Speed Boosters are quality made, using precision-machined brass with chromium plating on both the camera body and the lens side of the booster in order to ensure smooth mounting, quality aesthetic, and durability. This adapter has a detachable tripod foot that is compatible with Arca Swiss, Markins, and Photo Clam ball heads. This speed booster does not support the Olympus OM-D E-M1, E-M5, or E-M10 mirrorless cameras.