Number counts of galaxies in the Perseus field compared to COSMOS2020 in H_E and i_CFHT, both corrected for MW extinction. Other data from the literature are taken from (Driver et al. 2016, D16), while the Durham Cosmology Group’s counts are from the compilation available at the dedicated web page (http://star-www.dur.ac.uk/~nm/pubhtml/counts/counts.html). Left: H_E number counts. The COSMOS (from the Farmer catalogue described in Weaver et al. 2022, after removing masked regions and objects classified as stars) counts are derived from UltraVISTA H-band magnitudes converted to H_E using the equation D. 22 in Euclid Collaboration: Schirmer et al. (2023, solid dark cyan line). Perseus galaxy number counts in H_E are shown as a solid red line. The excess in the bright number counts can be explained by the contribution of Perseus cluster members. Right: i-band number counts. The COSMOS2020 data are from the HSC i-band, Perseus magnitudes are I_E (red solid line). The same excess at bright magnitudes is also observed.