Evolution of the erupting filament between 15:12 and 15:32 UT in SDO AIA 193 Å (top) and STEREO-A EUVI 195 Å direct images (a) and between 15:35 and 15:50 UT in base difference images (b). Blue markers show the upper tip of the filament observed by SDO AIA, and red markers indicate the matching points from the STEREO-A vantage point. Epipolar lines are shown in white. The yellow arrows indicate another, central part of the filament eruption. We note that the image scale of panels a and b is different. An animation of the reconstructions of panel b can be found in the online movie.