We took shots `` High ISO speed NR '' set Standard , default option.ISO figure noise starts become visible : ISO3200 ISO figure noise overwhelms image : ISO25600 Interested ? Help support ePHOTOzine using links.Amazon UK Amazon US Canon EOS 1D X III The Canon EOS-1D X Mark III designed professional sports wildlife photographers budget , delivers perfect results.The standard ISO range goes ISO100 ISO102400 , extended ISO50 ( Low ) , ISO819200.Noise reduction settings Disable ( ) , low , standard ( default ) , high.We took shots default setting.For lowest noise best detail possible would recommend using ISO50 ISO1600 , images low levels noise good levels detail.For lower light situations ISO3200 ISO25600 still provides good results , although noise increases detail reduced , fine detail going ISO6400 .