Adjusting the tone setting alters the shape of the 'S curve' used to map the linear image data captured by the sensor into the correct gamma. A lower contrast setting maintains more of the original data's dynamic range but leads to a flatter looking image. A higher contrast setting stretches the grayscale (dark to light) of the image and could lead to clipping of both shadow detail and highlights. The EOS-1Ds Mark III provides a wide range of adjustment with nine steps from -4 to +4.