Speed Booster has a magnification of 0.71x (“Makes lenses 0.71x wider”). Increase MTF & maximum aperture by 1 stop. Works with Full Frame lenses. Powered by camera body, electronic integration of aperture controlled by or from the camera body. NO Auto focus with FX9. More info: http://www.metabones.com/products/details/mb_spef-e-bm1
