  We study a noncommutative (NC) deformation of a charged scalar field,
minimally coupled to a classical (commutative) Reissner Nordstrom like
background. The deformation is performed via a particularly chosen Killing
twist to ensure that the geometry remains undeformed (commutative). An action
describing a NC scalar field minimally coupled to the RN geometry is manifestly
invariant under the deformed U(1) gauge symmetry. We find the equation of
motion and conclude that the same equation is obtained from the commutative
theory in a modified geometrical background described by an effective metric.
This correspondence we call duality between formal and effective approach. We
also show that a NC deformation via semi Killing twist operator cannot be
rewriten in terms of an effective metric. There is a dual description for those
particular deformations.
