  We simulate the hadroproduction of a t anti-t pair in association with a hard
photon at LHC using the PowHel package. These events are almost fully inclusive
with respect to the photon, allowing for any physically relevant isolation of
the photon. We use the generated events, stored according to the Les-Houches
event format, to make predictions for differential distributions formally at
the next-to-leading order (NLO) accuracy and we compare these to existing
predictions accurate at NLO using the smooth isolation prescription of
Frixione. We also make predictions for distributions after full parton shower
and hadronization using the standard experimental cone-isolation of the photon.
