Experimental data: contrast rms during the different iterations of PW+EFC implemented with the SPHERE calibration unit in a FDH of size 31λ/D × 31λ/D (in gray). The curve before compensation is plotted with a blue dashed line; the contrast after the last iteration is represented by a blue continuous line. The theoretical limit set by the APLC diffraction pattern is plotted with a red dashed line.