Response of the PWFS to modes with different value of wavefront RMS and for different partial correction levels (s = 0.00 arcsec correspond to diffraction limited conditions). Top-left: mode 0 (tip). Top-right: mode 10. Bottom-left: mode 100. Bottom-right: mode 499. Mode 0 is tip, 1 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. Sub-aperture size is 0.2 m. Optical gain is corrected considering an aberration RMS of 20 nm. Refers to the 8 m-class telescope case.