Fotasy MAEFBA Canon EF Lens to Micro 4/3 M43 Camera Focal Reducer Speed Booster Adapter (Black) Increase exposure to 1 stop, and you can use faster shutter speed to shoot an image Reduces focal length to 0.72x , to adjust the image size to near 1:1 so that the focal length of the image is close to actual focal length of the lens, e.g. 50mm x 1.5 x 0.72 = 54mm. With aperture ring, which allows to adjust Canon EOS Lens F-Stops Please note this adapter works with Canon EF Full frame lenses only. There is no electrical contacts in the adapter ring. Exposure and focus has to be adjusted manually. Automatic diaphragm, auto-focusing, or any other functions will not operated with using this adapter