Layout of the DM and WFS. The upper panel shows the layout of the 85-subaperture WFS and the 85-electrode monomorph DM of the SST AO system. The gray or white radial and azimuthal structures correspond to the electrodes of the DM, and the hexagonal structures correspond to the 85 lenslets. The large red circle corresponds to the pupil diameter, and the four lenslets highlighted in red correspond to the subapertures used for seeing measurements. The lower panel shows the layout of the 253-subaperture WFS, which is used to calibrate the waveŕronts (influence functions) produced by the 85 electrodes of the DM. Electrodes 73, 75, and 77, and their relation to microlens 16 (highlighted in read), for which electrode responses are shown in Fig. 7, are indicated in the lower panel.