Triangulation of the fine structure of the campfire 15. Left panels: HRI_EUV image. Right panels: SDO/AIA 171 Å image. Top panels: triangulation starting from the Solar Orbiter/HRI_EUV data. The centers of each campfire pixel used for the triangulation are marked with colored dots in the top left panel. The dots of the same color mark the corresponding points in the AIA image (top right panel). The orange cross corresponds to the point for which the height is plotted in Fig. 6. The corresponding epipolar line is shown in black. Middle panels: same as top panels but starting from the SDO/AIA 171 Å data. The bright pixel marked with the black triangle has no bright counterpart in the HRI_EUV data. Bottom panels: triangulation along an epipolar line (black lines).