It can be concluded that the parallel illumination and parallel receiving arrangement is the basic one of the shadow moir method and that other arrangements could inevitably produce errors because of the effect of non - parallel factor 分析结果表明，平行照射平行观察光场是影栅云纹法中的基本光场，其他光场均受非平行光因素的影响，不可避免地引入误差。
