This peper presents a method for measuring rigid body motion by white light digital speckle photography. Instead of using laser beam to generate the Young's fringe pattern from a specklegram as conventional speckle photography, a digital Fourier transformation is employed yield the Young's fringe pattern from whiCh rigid they motion can be computed by a new FFT phase shift method. Moreover, a new technique for improving the quality of the Young's fringe pattern is given. Theory together with experiment is demonstrated.