Based on high-resolution optical spectroscopy in the blue and the near infr
a-red spectral range, we derived velocity images (Doppler tomograms) of the
mass-donating secondary star and the accretion stream of the long-period e
clipsing polar V1309 Ori (RX J0515.41+0104.6). Combined with HST-spectrosco
py of high time resolution and optical photometry we were able to derive th
e main system parameters and to determine the accretion geometry of the bin
ary. The length of the eclipse of the white dwarf is Deltat(ecl) = 2418 +/-
60 s, the mass ratio Q = 1.37-1.63, and the orbital inclination i = 76.6 d
egrees -78.9 degrees. The surface of the secondary star could be resolved i
n the Doppler image of NaI absorption lines, where it shows a marked deplet
ion on the X-ray irradiated side. The accretion geometry proposed by us wit
h a nearly aligned rotator, co-latitude delta similar or equal to 10 degree
s, tilted away from the ballistic stream, azimuth chi similar or equal to -
35 degrees, explains the shape of the emission-line Doppler tomograms and t
he shape of optical/UV eclipse light curves.