Fundamental modes and lowest-order harmonics of the light curves presented in Fig. 2. The number of potentially observable modes and their relative amplitudes are strongly dependent on the type of the compact object, the inclination angle i, and the presence of a dipolar magnetic field. At small inclinations, the modes in the hard energy band are only visible, in the NS case, in a magnetised accretion disc with λ_D = 0.1, which makes this a particularly interesting tool for determining the parameter λ_D.