Free-run (FR) enables reliable high-speed data collection. (a) An SXDM phase-contrast image from FR data collected at 2500 Hz and a scan speed of 250 µm s−1, showing good agreement with (b) an SEM image of the object. Arrows in panels (a) and (b) highlight nanoscale features that can be recognized in both images. (c) Line profiles (light-grey lines) across 35 spokes of the test pattern from the second ring to the third. The average profile (black line) and its first derivative (dashed line) are shown. The scale bar in panel (a) corresponds to 1 µm and the greyscale indicates the quantitative phase delay in radians.