Comparison of the shock/front and MC-axis shapes deduced from in situ observations (in dashed black lines) with the corresponding shapes of a flux-rope that is imaged by STEREO-A HI 1 (shown at three times with color lines, Möstl et al. 2009). The shock shape (dashed black line) is deduced from Eqs. (15) and (16) for f_ICME = − 1 to 2, while the front shapes are set at the largest gradient intensity in HI 1 images. The axis shapes are from Janvier et al. (2013).