The image shifting technique, originally developed to resolve the directional ambiguity, also provides the opportunity to influence other parameters relevant to the PIV technique and thus, to enable its application of pulse separation and image shift is required to obtain high quality data of velocity vector fields even in strongly three dimensional flows. It has already been reported in the literature that errors will result from the fact thatthe projection of the 3D velocity vector of the real flow field into the 2D plane of recording is not a parallel projection, as it is mostly assumed for simplification, but a perspective projection