The techniques of high resolution moire photography and high speed photography have been combined to allow simultaneous measurement of both in-plane components of a transient displacement field with microsecond time resolution. A 150 lines mm-1 specimen grating is imaged onto a reference grating with a specially modified camera lens. The resulting real-time moire fringes are recorded with a high speed image converter camera. An automatic fringe analysis technique based on the 2-D Fourier transform method is used to extract the displacement information from the high speed sequences. The techniques are illustrated by the results of an investigation into the transient deformation of polymethyl methacrylate caused by solid particle impact.