Illustration of what improvement SKA observations will bring. Left: The 90% completeness of stellar mass of galaxies that can be observed above 5σ by SKA as a function of redshift, assuming 5 hour observation time for a single pointing. Right: Red squares denote the fraction of SKA detected galaxies that are above 27.5 mag in the SDSS-r band (approximate to LSST-r band depth) at different redshifts. At 4 < z < 6, pink cross represents the fraction of SKA detected galaxies that are above 26.1 mag in the SDSS-z band (aproximate to LSST-z band depth).