The visually observed luminosity of a discharge at low pressure and current was analyzed experimentally and interpreted by nonlocal character of the electron velocity distribution function (EVDF) formation under these conditions. The measurements were conducted in Ne discharge at pressures ∼ 1 Torr and currents 1-40 mA in a tube with the radius R = 1,5 cm. The instrumental functions A(r/R) measured by scanning of a point source was shown. It was found that in the nonlocal kinetic theory the luminosity contraction is a consequence of the EVDF formation by the action of diffusive electron flights in radial field of the positive column.