  We study degeneracies between parameters in some of the widely used
parametrized modified gravity models. We investigate how different observables
from a future photometric weak lensing survey such as LSST, correlate the
effects of these parameters and to what extent the degeneracies are broken. We
also study the impact of other degenerate effects, namely massive neutrinos and
some of the weak lensing systematics, on the correlations.
