Density plots of various parameters in relation to the significance of a_G, the amplitude of the small-separation binary model fit to the G-band photometry (Eq. 5). The white vertical line indicates a significance threshold of 6, above which the fitted amplitude is more likely due to a scan-angle-dependent signal. In the top panels, the same low thresholds as in Fig. A.3 are repeated at 3 and 9. The second and third panels show the strong relation between high-amplitude significance and high r_ipd, G or r_exf, G, respectively (see Sect. 6.4 for further discussion). Plots for N_3band ≥ 20 and N_noEpsl, G ≥ 20.