 There are comparisons with the Canon EOS-1D Mark IV, which is rated 1.3 stops lower by DxOMark on their low-light ISO score (1320 ISO vs. 3253 ISO for the D3s).Low-noise videos are valuated useful.While not officially documented in user's manual, D3s indeed features the full manual control in D-Movie mode, including aperture, shutter speed and ISO.