  We use galaxy-galaxy lensing to study the statistical properties of the dark
matter halos of galaxies. Our data is taken from the COMBO-17 survey which has
imaged 1 square degree in 17 optical filters giving accurate photometric
redshifts and spectral classification down to R=24. This allows us to study
lens galaxies at $z=0.2-0.7$. Shapes are measured from deep $R$-band images
taken at the best seeing conditions ($0\farcs 8$ PSF). We model the lens
galaxies as singular isothermal spheres (SIS). Investigating the dependence of
the velocity dispersion on the luminosities of the lens galaxies we are able to
reproduce the Tully-Fisher/Faber-Jackson relation. Further we find a larger
lensing signal for early-type galaxies than for the late-types. However, when
testing the dependence of the velocity dispersion on radius we see clear
deviations from the SIS model. The velocity dispersion is first rising and then
declining again. This is exactly what is expected for lens galaxies that can be
modeled by Navarro-Frenk-White (NFW) profiles.
