Metabones Canon EF to BMPCC Speed Booster (Black Matt) Industry's best aperture ring covers a 8-stop range with half-stop markings, clearly indicating actual number of f-stops Increase maximum aperture by 1 2/3 stop (with a maximum output aperture of f/0.74) Increase MTF Makes lens 0.58x wider The tripod foot is detachable and compatible with Arca Swiss, Markins, Photo cam ball heads