  We discuss by a Poynting vector analysis how the losses of a negative index
material (NIM) affect the resolution performances of a Veselago-Pendry lens and
we analyze those performances in the framework of the Abbe criterion. Both the
limit of high losses and low losses are explored. We find that the impedance
matched NIM is able to resolve 30% better than the limit imposed by the Abbe
criterion even when the imaginary part of the refractive index (the material
losses) exceeds the absolute value of the real part of the refractive index.
The NIM is described by a lossy Drude model with equal permittivity and
permeability. By increasing the damping parameter of the Drude model we also
explore the regime where both permittivity and permeability are positive and
point out the conditions under which the metamaterial is still able to
super-resolve.
