Evolution of the mean contrast in the DH during HOWFS (using SM) as a function of iterations during different intervals: without LOWFC in blue in sections (0) and (2), and with it in red in sections (1) and (3). SM is turned off in section (4). In (4), the mean contrast is measured while LOWFC loop is running (green). Once per contrast measurement, the LOWFC loop is interrupted and reset to its initial command in (4) to get an open-loop measurement, in black. When on, the HOWFC loop runs at 0.05 Hz and the LOWFC loop at 30 Hz.