Moiré topography using developed recording methods

Abstract Where moire topography is used to record the shape of objects of approximately cylindrical form or that of a series of such objects, a scanning method with a slit camera can be employed. One such method takes photographs by combining conventional shadow type and projection type moire topography with a slit camera. Laser methods of line projection combined with a scanning method developed from the projection type of moire topography are also utilised. The main features of the latter method are that it is not affected by any diffraction effect caused by the grid and that highly accurate recording can be achieved with excellent image quality using the properties of the laser beam. Another distinct advantage is that it is capable of recording the shape of a self-luminous object without contacting by selection of laser wavelenghts and matching optical filters. The laser scanning method can therefore be considered to have considerable potential for future applications.