The Canon FD Lens to Micro Four Thirds Mount Camera Speed Booster from Metabones allows a full frame Canon FD lens to be mounted to a Micro Four Thirds mount camera and in doing so, increases the angle of view 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 an Micro Four Thirds sized sensor, it transmits a larger area of light than the smaller sensor was built to accept and therefore the angle of view of the lens decreases and the equivalent focal length increases. The Speed Booster condenses light from the lens and projects it onto the smaller sensor allowing the sensor to utilize all of the lens' light and effectively produce 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.
Metabones Speed Boosters are quality made, using precision-machined brass with chromium plating on both the camera-body and the lens sides 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.
Although the lens will fit physically, automatic diaphragm (AE metering), or other auto functions are not retained using this speed booster. The Canon FD to Micro Four Thirds Speed Booster has been updated and is now compatible with the Olympus OM-D E-M1 camera.