633 nm He-Ne laser calibration data illustrating the response of a 6-mode HMWS to controlled wavefront aberrations. a) PSF with no induced wavefront error and b) with 1.5 rad of defocus error applied via the SLM, showing the asymmetric response of the Z₃ ± defocus WFS spot pair, indicated top-right/bottom-left. Filter and SLM reflection ghosts are present below the zeroth-order PSF, though these are sufficiently separated from the PSF copies to ensure no interference with HMWS performance.