  Nonclassicality filters provide a universal method to visualize the
nonclassicality of arbitrary quantum states of light through negativities of a
regularized Glauber-Sudarshan $P$ function, also denoted as nonclassicality
quasiprobability. Such filters are introduced and analyzed for optimizing the
experimental certification of nonclassical effects. An analytic filter is
constructed which preserves the full information on the quantum state. For
balanced homodyne detection, the number of data points is analyzed to get the
negativities of the nonclassicality quasiprobability with high statistical
significance. The method is applied to different scenarios, such as phase
randomized squeezed vacuum states, single-photon-added thermal states, and
heralded state engineering with array detectors. The generalization to
visualize quantum correlations of multimode radiation fields is also
considered.
