Dimming evolution for 1 October, 2011 CME at (a) the maximum of the impulsive phase (reached 12 min after its start); (b) 18 min after the start of event; (c) at the end of the impulsive phase (30 min after the maximum of the impulsive phase); and (d) 2.5 h after the start. The blue lines indicate 12 angular sectors and the color bar shows when each dimming pixel was detected for the first time.