Dependence of the bias as a function of P3/P0_ideal (lower axis) and w_ideal (upper axis). Left: absolute value of the bias before correcting. Right: absolute value of the remaining bias after applying the bias correction and . The different counts are color-coded: 30 000 black, 1000 red, 500 blue, 200 green. B_P3 is shown using thick lines, B_w is represented by different thin lines. The dependencies are fits to all 121 simulated cluster images using the BCES linear regression method (Akritas & Bershady 1996).