Left panel: map of the average extinction affecting the ONC candidate members. The color bar shows the correspondence between the gray scale and visual extinctions. We also mark the boundaries of the three regions outlined by R10. Central panel: ISPI K_S mosaic of the surveyed ONC. The overplotted contours represent the A_V = 3 (yellow line) and the A_V = 6 (red line) levels. Right panel: uncertainty on our derived ON extinction map. See Fig. B.2 for larger views of the left and central panels.