  The potential of cosmic shear to probe cosmology is well recognized and
future optical wide field surveys are currently being designed to optimize the
return of cosmic shear science. High precision cosmic shear analysis requires
high precision photometric redshift. With accurate photometric redshifts, it
becomes possible to measure the cosmic magnification on galaxies by galaxies
and use it as a probe of cosmology. This type of weak lensing measurement will
not use galaxy shapes, instead it will strongly rely on precise photometry and
detailed color information. In this work it is shown that such a measurement
would lead to competitive constraints of the cosmological parameters, with a
remarkable complementarity with cosmic shear. Future cosmic shear surveys could
gain tremendously from magnification measurements as an independent probe of
the dark matter distribution leading to a better control of observational and
theoretical systematics when combined with shear.
