Superposition of the evolution with flux for nearest pixel correlations (coefficients R_0,1R_1,1R_1,0) for read out channels 1 to 8 of CCD E2V-250. The whole dynamical range shows a threshold where correlations strongly increase: first R_0,1, a correlation in Y direction, and near full well, R_1,0, a correlation in X direction. The diagonal correlation R_1,1 does not exhibit any threashold. This is expected since neither transfer nor read out could contribute to correlate pixels in this direction. The vertical dark line indicates the early threshold of R_0,1.