Sigma 12-24mm f4.5-5.6 EX DG mounted on a Canon EOS 5D Mark II (for Canon)Sigma 12-24mm f4.5-5.6 EX DG mounted on a Nikon D3x (for Nikon)The built is quite consistent in both offerings as they’ve obtained the same results on the DxOMark Score:10 at 12mm f/4.5 mounted on a Canon EOS 5D Mark II11 at 17mm f/5 mounted on a Nikon D3x As mentioned earlier, in spite of the quality of the cameras used for testing the score is pretty low for this lens and this could be explained by the following reasons:Due to its range of aperture this