Intramolecular "electron lamp" throws bright shadows: Angle-scanned X-ray photoelectron diffraction (XPD) allows the absolute configuration of adsorbed molecules to be determined in a straightforward way. Owing to intramolecular scattering, the C1s XPD pattern of tartaric acid adsorbed on Cu(110) (see picture; Cu brown, C blue, O red) has pronounced forward-focusing maxima that directly yield the absolute molecular conformation without the need for complex calculations.