Talbot plane patterns: grating images or interference effects?

It has been widely said that with the Talbot effect a grating makes images of itself unaided. However, the effect as produced by simple amplitude gratings was recently redefined in terms of interference-pattern visibility or contrast instead of self-imaging. Then, by starting with a pair of slits instead of the usual infinite grating, a new and more general description of the effect was developed. Now numerical methods and tools from physical optics are used further to characterize the influences of the grating, light parameters, and the position of the plane of observation on pattern form, fine structure, band positions, and phases. It is found that none of the patterns in the Talbot planes actually approximates grating images in terms of all of these properties. Hence the Talbot effect should be defined in terms of interference effects, not grating images.