Examination of an object particularly by more ray deflection mappng

A method and apparatus for moire ray deflection map ping for determining properties of an object in which a point source of light producing a diverging beam of direct light is passed through a first optical system in cluding the object to be examined, which system re traces the light in the form of a converging beam of reflected light from the examined object back towards the point source. The converging beam of reflected lightisintercepted before reaching the point source and is passed through a second optical system which colli mates the beam of reflected light. The collimated beam is then directed through first and second gratings at a preselected angular orientation with respect to each other to produce moire fringe patterns providing an indication of the properties of the examined object. An important advantage in the above novel method is that the same setup can be used for measurements of both phase objects and specular surfaces.