The black Canon EF Lens to Micro Four Thirds Speed Booster "S" Version
is designed to be used on Micro Four Thirds cameras with an "active" mount as opposed to those with a "passive" mount and is therefore compatible with Olympus OM-D cameras, Panasonic GH4 and the Blackmagic Pocket Cinema Camera but not with the Blackmagic Cinema Camera 2.5K.
This EF to MFT Speed Booster 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. 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. Image stabilization on lenses that provide it is supported and EXIF data transferred as well. No external power source is required as the speed booster is powered by the camera and houses a 32-bit processor.
Metabones Speed Boosters are made of 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.