Prompt photon, Drell-Yan and Bethe-Heitler processes in hard photoproduction

We present prospects and requirements for the study at HERA of hard photon processes which generate high $p_T$ photons in the final state, and processes which generate Drell-Yan lepton pairs.Comment: 6 pages, 3 embedded figures. To appear in the proceedings of the workshop "Future physics at HERA