EFFECT OF CAMERA SPATIAL-RESOLUTION ON FRINGE CONTRAST IN DIGITAL SPECKLE CORRELATION INTERFEROMETRY

In digital speckle correlation interferometry, the camera used is typi cally unable to fully resolve the speckle pattern. Consequently, there is often a tendency to utilize cameras with better spatial resolution in order to obtain improved fringe contrast signals. However, it is d emonstrated in this paper that the fringe contrast signal is effective ly independent of camera spatial resolution. In fact, the use of highe r spatial resolution cameras may even result in a catastrophic corrupt ion of the fringe contrast against deformation phase waveform if the m agnitudes of phase fluctuation are sufficiently large.