Using a digital still camera for shearography: Preliminary experiments and observations

We have used a simple digital still camera, instead of a conventional video-rate camera, to capture high-resolution images in a shearographic system. The high-resolution, compressed JPEG still images (of 18 megapixel resolution) are only generated by the camera on command from the controlling PC. We successfully generated shearograms from the still images, which are indicative of the applied stresses on the test object. The test object in this case is a center-loaded metal plate, fixed at the edges. The use of a digital still camera simplifies the electronic part of the shearographic system, and prevents the generation of unnecessary images. We propose to apply the system in several different applications.