  Images obtained with the CTIO 4-m telescope and the MOSAIC-2 wide field
camera in [O III] 5007 and H\alpha on-band and off-band filters are analyzed to
search for emission lines objects in the galaxy NGC 6822. In particular we
search for PN candidates. In addition, data of a sub-sample of objects obtained
with ESO VLT-FORS2 are used to calibrate the MOSAIC imaging. A large number of
line emission regions were detected, for which we measured instrumental
magnitudes in all the filters. Based on some criteria to distinguish between
PNe and compact HII regions, we found 26 PN candidates, increasing the known
sample in 8 objects. Also we detected a number of compact HII regions and 20
stellar objects emitting in Halpha. For all the objects we present coordinates,
instrumental magnitudes and nebular [O III] and Halpha+[N II] fluxes. The
observed PNLF for the PN [O III] 5007 magnitudes and the cumulative PNLF were
calculated. We confirm that the PNLF presents a dip similar to the one detected
for the SMC at 2.5 mag down the maximum. The cumulative PNLF returns a value
M^\star_{5007}=-3.71^{+0.21}_{-0.42} for the peak absolute magnitude of the
PNLF which is faint compared to the value expected for galaxies with
metallicity similar to the one of NGC 6822 but similar within uncertainties.
  From our best fit to the observed PNLF we obtained a rough distance modulus
m-M = 23.64 ^{+0.23}_{-0.43} mag, which agrees within uncertainties with recent
values reported in the literature. The number of PN in the brightest 0.5 mag
normalized to the galactic bolometric luminosity, alpha_{0.5} was estimated to
be (3.8^{+0.90}_{-0.71}) E-9, which is similar to the values derived for
galaxies with recent star formation and small galaxies (M_B fainter than - 18
mag).
