The Microscope's Fast Scan Lost Signal Sideways

Direct probe imaging and sub-frame diffraction analysis found a settling time of several tens of microseconds, long enough to matter as detectors move toward microsecond dwell. A phase-correlation alignment procedure estimated and corrected the intra-dwell smear, restoring signal across spatial frequencies with the largest gains at the larger scan steps used for low-dose biological imaging. Because the correction operates on existing data, it requires no microscope modification; its reported performance still depends on the tested scan conditions.