Hα HST images presented at the same angular scale. Each panel is 12 arcsec per side. The intensity scale is linear. The names are indicated in each panel. The first three columns show PNe in the bipolar phase while the rightmost column shows the proposed post-bipolar phase (see text). Six PNe are assumed to belong to the Galactic bulge while the smallest and largest, both shown in the third column, are assumed to be located behind and in front of the bulge, respectively.