Number of accreting BHs brighter than m_200W per NIRcam field of view as a function of their apparent magnitude m_200W assuming negligible obscuration for different redshift bins in the range 5 < z < 15. Here, we split the BH population in three separate bins of BH mass, represented by different coloured lines (see the legenda). As in Fig. 2 vertical and horizontal lines represent the magnitude and density limit for different surveys: JADES-Deep (short-dashed), JADES-Medium (dot-dashed), CEERS (dotted), PRIMER (dashed), COSMOS-WEB (long dashed). The BH population that would be observable by each survey depends on its area and sensitivity, with COSMOS-WEB sampling a large enough area to detect a few of the rarest systems with Log(M_BH/M_⊙) > 8 at z < 7, and JADES-Deep being capable of detecting the heavy BH seeds with masses 4 < Log(M_BH/M_⊙) < 6 out to z ∼ 13−14.