[en] UBV Light Curves of the eclipsing binary system PV Cassiopaiae have been investigated using recently developed frequency-domain techniques. This analysis is based on Kopal's new theory of the study of the light variations, between minima as well as within eclipses, of eclipsing binaries whose components undistorted or distorted by axial rotation and mutual tidal action. A method for the distinguishing of the photometric proximity and eclipse effects directly from the obersved data is also presented. In this method no rectification is needed. The automated method has been tested succesfully on the light curves of PV Cassiopeiae. Finally, a comparative discussion is given of Kopal's and Kitamura's methods of the light curves analysis. (orig.)