Sky coverage as a function of flux for the 11 CLASH cluster fields. The thick solid curve shows the sky coverage in the source plane as a function of the de-lensed flux in the soft (left panel) and hard (right panel) bands. The thick dotted curve instead shows the same sky coverage in the source plane, but as a function of the observed flux. The sky coverage in the source plane was used to compute the delensed log N–log S. The sky coverage in the lens plane is also shown as a function of the delensed flux (continuous curve) and of the observed flux (thin dotted curve). The horizontal dashed line indicates the total solid angle, by the criterion μ_max > 1.5. The black curve shows the sky coverage of the 7 Ms CDFS survey in the corresponding energy ranges (Luo et al. 2017). The hard-band flux limits in Luo et al. (2017) given in 2−7 keV are converted into 2−10 keV by assuming Γ = 1.8.