The speed booster ultra from metabones allows a full frame or aps c nikon af g f mount dslr lens to be mounted onto a fuji x mount compact system camera such as the fuji x pro2 like the previous metabones speed booster model the updated ultra has a magnification of 071x so it effectively reduces the crop factor of mirrorless cameras with dx sized sensors from 15x to 107x however the new optical design in the ultra uses advanced 5 element4 group optical design incorporating ultra high i