  It is shown that perfect imaging of a point source both in near- and
far-field regions contradicts electrodynamics although ``superlensing'' is
impossible only in the far-field region. These general statements are
illustrated by detailed study of evanescent wave propagation in a photonic
crystal that is known to be a left-handed medium. An analytical expression for
the intensity distribution near the far-field focus is obtained. This
distribution contains some novel features and establishes a new ``diffraction
limit'' for flat lenses. It is generalized for multiple sources located at
different points. The distribution is in very good agreement with computer
simulation.
