Mean DH contrast while PW with single-actuator probes and SM are running, 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 is running. Once per contrast measurement, the LOWFC is interrupted and reset to its initial command in (4) to get an open-loop measurement, plotted in black. When on, the HOWFC loop runs at 0.4 Hz and the LOWFC loop at 80 Hz.