Three-dimensional penetration measurements using digital speckle photography

This paper describes a simple optical technique for simultaneous photographic recording of high-speed events in stereo, using a translated lens stereoscopic system. An optical wedge is used to refract two spatially separated images together and the result is photographed as a split-frame. The technique is applied to the bulging of a plate on impact by a cylindrical rod. Methods of analysing in-plane movements in each stereoscopic image include use of a grid and a speckle pattern. The different in-plane movements between the two images, owing to perspective differences, cart be used to extract topological information.