0.71x Speed-booster: focal length is multiplied by 0.71 based on the original (equivalent focal length = actual focal length x 0.71), which helps enlarge 1 level aperture.
Quick and precise AF (auto-focusing); support aperture adjustment; parameters of aperture, shutter speed, exposure and ISO can be controlled directly from camera side.
More Features: light in weight (162.5 g); support lens IS function; EXIF signal transmission; matte metal surface treatment; a micro USB port for upgrading firmware and fixing bugs; designed with a manual aperture adjustment ring.