Limiting magnitudes or modal depths (5σ) of the photometric filters used in this work within the COSMOS field. The line widths represent the FWHM of the filter transmission curves, and the depths are reported in Table 1. The HSC and VISTA filters are shown in black and orange, respectively, and the four Euclid filters are labelled. We also show example SEDs of a UCD and a LBG with the solid and dashed lines, respectively. The model photometry for the UCD and the LBG are shown by the stars and circles respectively and are colour-coded by their filters. Note that the Euclid NIR filters cover the gaps between the VISTA filters. These wavelengths are inaccessible from the ground due to the atmospheric absorption.