PWFS sensitivity in partial correction as a function of mode number and seeing value expressed as the RMS of the slope for an aberration with a wavefront RMS of 1nm. Mode 1 is tip, 2 is tilt and the other modes are Karhunen–Loève modes. Solid lines correspond to a non-modulated PWFS and dashed lines correspond to a PWFS with a modulation radius of 3λ/D. Top-left: sub-aperture size of 0.2 m, top-right, sub-aperture size of 0.4 m. Bottom-left: sub-aperture size of 0.6 m. Bottom-right: sub-aperture size of 0.8 m for the 8 m-class telescope case.