  The recent status of hard thermal photon production in relativistic heavy ion
collisions is reviewed and the current rates are presented with emphasis on
corrected bremsstrahlung processes in the quark-gluon plasma (QGP) and
quark-hadron duality. Employing Bjorken hydrodynamics with an EOS supporting
the phase transition from QGP to hot hadron gas (HHG), thermal photon spectra
are computed. For SPS 158 GeV Pb+Pb collisions, comparison with other
theoretical results and the WA98 direct photon data indicates significant
contributions due to prompt photons. Extrapolating the presented approach to
RHIC and LHC experiments, predictions of the thermal photon spectrum show a QGP
outshining the HHG in the high-pT-region.
