  [abridged] We construct lightcones for the semi-analytic galaxy formation
simulation of Guo et al. (2011) and make mock catalogues for comparison with
deep high-redshift surveys. Photometric properties are calculated with two
different stellar population synthesis codes (Bruzual & Charlot 2003; Maraston
2005) in order to study sensitivity to this aspect of the modelling. The
catalogues are publicly available and include photometry for a large number of
observed bands from 4000{\deg}A to 6{\mu}m, as well as rest-frame photometry
and intrinsic properties of the galaxies. Guo et al. (2011) tuned their model
to fit the low-redshift galaxy population but noted that at z > 1 it
overpredicts the abundance of galaxies below the "knee" of the stellar mass
function. Here we extend the comparison to deep galaxy counts in the B, i, J, K
and IRAC 3.6{\mu}m, 4.5{\mu}m and 5.8{\mu}m bands, to the redshift
distributions of K and 5.8{\mu}m selected galaxies, and to the evolution of
rest-frame luminosity functions in the B and K bands. The B, i and J counts are
well reproduced, but at longer wavelengths the overabundant high-redshift
galaxies produce excess faint counts. The predicted redshift distributions for
K and 5.8{\mu}m selected samples highlight the effect of emission from
thermally pulsing AGB stars. The full treatment of Maraston (2005) predicts
three times as many z~2 galaxies in faint 5.8{\mu}m selected samples as the
model of Bruzual & Charlot (2003), whereas the two models give similar
predictions for K-band selected samples. Although luminosity functions are
adequately reproduced out to z~3 in rest-frame B, the same is true at
rest-frame K only if TP-AGB emission is included, and then only at high
luminosity. Fainter than L* the two synthesis models agree but overpredict the
number of galaxies, another reflection of the overabundance of ~10^10M\odot
model galaxies at z > 1.
