The theory and experimental results of diffraction-limit of moire contouring are described. The moire fringes on an object viewed in monochromatic light from a point source are considered.
The diffraction-limit of moire contouring for practical purpose, i. e., the depth in which distinct fringes are observed, is determined experimentally by Fourier Image Analysis.
The effective depth of fringes in the neighborhood of Fourier Image of the grating is twice as much as in the region close to the grating.
To know this effective depth is an important matter, when putting moire contouring into practice.
View full abstract