A whole-field projection-speckle technique to measure out of plane displacements of initially flat structures has been presented. The method is based on digital correlation of images obtained from a TV camera. An improved digital-correlation function has been derived and described along with the analysis scheme. An instrumentation system based on a desktop computer has been set up to implement the method. Experimental results from simple static tests have been used to validate the technique. © 1998 Society for Experimental Mechanics, Inc.