  I discuss mechanisms of heavy quark production in (real) photon-nucleon and
(real) photon - (real) photon collisions. In particular, I focuse on
application of the Saturation Model. In addition to the main dipole-nucleon or
dipole-dipole contribution included in recent analyses, I propose how to
calculate within the same formalism the hadronic single-resolved contribution
to heavy quark production. At high photon-photon energies this yields a
sizeable correction of about 30-40 % for inclusive charm production and 15-20 %
for bottom production.
