Reconstruction error of Fig. 10 (4c). The unit are in radians. (a) Same reconstruction error than Fig. 10 (4c), at an optimized scale. (b) Orders lower than seven cycles per pupil of the reconstruction error (a), obtained with a cut on the PSD and an inverse Fourier Transform. (c) Difference between the phase maps (a) and (b). Patterns of a few cycles per pupil are visible and can be easily identified using a spatial filter. They correspond to the peak at around five cycles per pupil of the PSD of Fig. 10 (5c). It has been shown in Sect. 5 that with a coronagraph, the COFFEE algorithm generates extra low-order aberrations.