The use of non-steady-state photo-EMF effect for measuring the contrast distribution and its application as an adaptive detector for Talbot interferometry have been investigated both theoretically and experimentally. The main results of this investigation can be summarized as follows: 1) For the first-time detailed theoretical analysis of non-steady-state photo-EMF current induced by arbitrary 1-D periodical light pattern using the model of monopolar photoconductor with a single impurity center was performed. 2) Theoretically predicted axial dependencies of photo-EMF current were observed at different experimental conditions using different GaAs detectors. The main results of the theoretical analysis for two limiting cases (large and small diffusion length) were confirmed experimentally. 3) The comparative analysis (theoretical and experimental) of the photo-EMF based-method against the conventional CCD-based methods (RMS and semivariogram techniques) for measuring contrast distribution and for localization of Talbot self-images was realized. 4) The possibility of practical application of the adaptive photo-EMF detectors and the Talbot effect for effective distance measurements from a mirror-like target was demonstrated experimentally.