  We introduce a novel and concise methodology to detect the parity of atomic
and molecular orbitals based on photoelectron holography, which is more general
than the existing schemes. It fully accounts for the Coulomb distortions of
electron trajectories, does not require sculpted fields to retrieve phase
information and, in principle, is applicable to a broad range of electron
momenta. By comparatively measuring the differential photoelectron spectra from
strong-field ionization of N$_{2}$ molecules and their companion atoms of Ar,
some photoelectron holography patterns are found to be dephased for both
targets. This is well reproduced by the full-dimensional time-dependent
Schr\"{o}dinger equation and the Coulomb quantum-orbit strong-field
approximation (CQSFA) simulation. Using the CQSFA, we trace back our
observations to different parities of the 3$p$ orbital of Ar and the
highest-occupied molecular orbital of N$_{2}$ via interfering Coulomb-distorted
quantum orbits carrying different initial phases. This method could in
principle be used to extract bound-state phases from any holographic structure,
with a wide range of potential applications in recollision physics and
spectroscopy.
