  The statistics of giant arcs and large separation lensed quasars provide
powerful constraints for the parameters of the underlying cosmological model.
So far, most investigations have been carried out using pure dark matter
simulations. Here we present a recipe for including the effects of baryon
cooling (i.e. large galaxy formation) in dark matter N-body simulations that is
consistent with observations of massive galaxies. Then we quantitatively
compare lensing with and without applying this baryon correction to the pure
dark matter case. Including the baryon correction significantly increases the
frequency of giant arcs and lensed quasars, particularly on scales of 10 arcsec
and smaller: the overall frequency of multiple images increases by about 25%
for source redshifts between z_s = 1.5 and 7.5 and splittings larger than about
3 arcsec. The baryon rearrangement also slightly increases the fraction of
quadruple images over doubles.
