  Recently, Holz and Wald (1998) have presented a method for determining
gravitational lensing effects in inhomogeneous universes. Their use of
realistic galaxy models has been limited to the singular, truncated isothermal
sphere with a fixed mass. In this paper, their method is generalized to allow
for matter distributions more accurately describing the actual properties of
galaxies, as derived from observations and N-body simulations. This includes
the density profile proposed by Navarro, Frenk and White, as well as a
distribution of galaxy masses. As an example of the possible applications of
the method, we consider lensing effects on supernova luminosity distributions.
  We find that results for different mass distributions of smooth dark matter
halos are very similar, making lensing effects predictable for a broad range of
halo profiles. We also note, in agreement with other investigations, that one
should be able to discriminate smooth halos from a dominant component of dark
matter in compact objects. For instance, a sample of 100 supernovae at redshift
z=1 can, with 99 % certainty, discriminate the case where all matter is in
compact objects from the case where matter is in smooth halos.
