Photon correlators in U(1) pure gauge theory for different lattice act
ions are considered under the Lorentz gauge condition. They are shown
to depend strongly on the gauge fixing ambiguity and on the correspond
ing existence of Dirac sheets. For the Coulomb phase a gauge fixing al
gorithm is proposed which avoids Dirac sheets and allows to find the g
lobal extremum of the non-local gauge condition.