I discuss mechanisms of heavy quark production in (real) photon-nucleon and (real) photon-(real) photon collisions. In particular, I focus 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. Adding all possible contributions to e⁺e^- \rightarrow b \bar bX together removes a huge deficit observed in earlier works but does not solve the problem totally.

PACS numbers: 12.38.Bx, 12.38.Lg, 12.40.Vv