  We study unquenched QED in four dimensions using renormalised Schwinger-Dyson
equations and focus on the behaviour of the fermion and photon propagators. For
this purpose we use an improved Kizilersu-Pennington (KP) vertex which respects
gauge invariance, multiplicative renormalizability for the massless case,
agrees with perturbation theory in the weak coupling regime and is free of
kinematic singularities. We find that the KP vertex performs very well as
expected specially in comparison with other vertex choices. We find that the
Landau pole problem familiar from perturbative QED persists in the
nonperturbative case with the renormalised inverse photon propagator having
zero crossing.
