Bias induced by the QACITS outer estimator, as a function of the Lyot stop shift, in units of percent of the telescope entrance pupil diameter (i.e., 1% corresponds to 11 cm at the scale of the telescope pupil). The red crosses show the bias induced by the outer estimator. The blue triangles are the inner estimator values as measured at the biased position. The light blue squares are the same estimates scaled by an adjustment factor of 0.7. This factor is computed as the slope ratio of the best linear model fitted on the actual bias and inner estimate at small Lyot shift amplitudes (<2%), shown as dashed lines.