Point source number counts in the point-source subsurvey region of each field as a function of the 0.5-2 keV (blue) and 2–10 keV (green) Galactic-absorption-corrected fluxes. For representation, the cumulative number density (y-axis) is multiplied by the flux limit in units of (10⁻¹³ erg cm⁻² s⁻¹). The lower boundary of the plotted flux range corresponds to 50% sensitivity (50% of the total area in the sky coverage curve) in the soft band and 30% sensitivity in the hard band. The shaded region indicates the 1-σ uncertainty calculated as the square root of the source number. For comparison, we plot the number counts from three previous extragalactic X-ray surveys. The A3391 field is divided into two parts, as displayed in the bottom panels. For ES0102, the dashed lines indicate the number counts with the SMC stars removed.