  The luminosity of X-ray pulsars is their key parameter determining the
geometry and physical conditions of the accretion flow both on the spatial
scales of a binary system and on much smaller scales of emitting regions
located close to the stellar surface. Traditionally, the luminosity of X-ray
pulsars is estimated out of the X-ray energy flux averaged over the pulsed
period and the estimated distance to the source. Due to the anisotropy of X-ray
emission, the luminosity estimated on the base of the observed pulse profile
can differ from the actual one. Super-critical X-ray pulsars with accretion
columns are of particular interest because the X-ray flux from columns is a
matter of strong gravitational lensing by a neutron star. Using toy model of an
accretion column, we simulate beam patterns in super-critical X-ray pulsars,
construct theoretical pulse profiles for different geometries and mutual
orientations of pulsars and distant observers and show that despite strong
light bending, the typical deviation of the apparent luminosity from the actual
one is $\sim 20\%$ only, and in $\sim 90\%$ of cases, the apparent luminosity
$0.8 L\lesssim L_{\rm app}\lesssim 1.25 L$. However, the shape of the pulse
profiles is strongly affected by the geometry of the emitting region. We show
that the appearance and growth of accretion columns tend to be accompanied by
an increase of observed pulsed fraction, which is in agreement with the recent
observations of bright X-ray transients.
