  When the logarithmic slope of the galaxy counts is lower than 0.4 (this is
the case in all filters at large magnitude), the magnification bias due to the
lens makes the number density of objects decrease, and consequently, the radial
distribution shows a typical depletion curve. In this paper, we present
simulations of depletion curves obtained in different filters for a variety of
different lens models - e.g., a singular isothermal sphere, an isothermal
sphere with a core, a power-law density profile, a singular isothermal
ellipsoid and a NFW profile. The different model parameters give rise to
different effects, and we show how the filters, model parameters and redshift
distributions of the background populations affect the depletion curves. We
then compare our simulations to deep VLT observations of the cluster
MS1008--1224 and propose to constrain the mass profile of the cluster as well
as the ellipticity and the orientation of the mass distribution. This
application is based solely on deep photometry of the faint background
galaxies. We finally give some possible applications of this method, useful for
cluster lenses.
