We discuss the calibration of the wings of the Chandra point spread function. In order to achieve high resolution imaging, the X-ray mirror surfaces must be extremely smooth in order to suppress the effects of scattering from microroughness. In the Chandra program, surfaces with only 1.3-3 Å roughness were achieved over more than 90% of the mirror length. We describe the current state of the calibration of the Chandra PSF wings, incorporating the results of a deep observation of the X-ray source Her X-1. The galactic Hydrogen column density (NH) to Her X-1 is small, reducing the amplitude of any astrophysical dust scattering halo which would contaminate the mirror scattering wings. The X-ray data clearly show the shadows of the mirror support struts, confirming that the observed halo is predominantly due to mirror scattering. The extreme brightness of the source allows the energy dependence of the PSF wings to be probed with good statistics. The deep observation (heavily piled up in the core) is combined with a zero order gratings observation (unpiled in the core) to construct an energy-dependent profile.