Experiments have confirmed that one technique, developed several years ago at NIST, can enable optical microscopes to measure 3D shape of objects at nanometer-scale resolution. Results could make said technique, Through-focus Scanning Optical Microscopy (TSOM), useful for QC regarding manufacture of such nanoscale devices as next-generation microchips. In 3D shapes, TSOM can detect variations of <1 nm size among objects <50 nm across.