Results of the light curve modelling test. On the x-axis the S/N quantity is defined in the text. y-axes are the relative uncertainties in radius ratio k, u ₊  combination of the two quadratic limb darkening coefficients used, in the scaled semi-major axis (for brevity we used the notation of a only instead of a/R_s in the third panel from top) and in the impact parameter b, from top to bottom, expressed in percentages. The solid lines show the relative uncertainties defined as the standard deviations of the differences of the modelled and the input values normalized to the input values at certain S/N-values.