The High Resolution Optical Measurement of Edge Radius (HOMER) diagnostic on the Mega Ampere Spherical Tokamak Upgrade (MAST-U) has been upgraded with a modern line-scan camera and data acquisition system, enabling high spatial and temporal resolution measurements of visible emission from the plasma edge. The diagnostic is designed to detect the plasma boundary for real-time control and to study edge-localized modes (ELMs), the pedestal region, and neutral density profiles. An absolute radiometric calibration was performed to express measurements in units of radiance, and a spatial calibration was carried out to map pixels to radial coordinates within the vacuum vessel. Initial experimental results from an ELMy H-mode discharge demonstrate that HOMER resolves the separatrix position, tracks the emissivity during ELMs, and enables inference of neutral density profiles consistent with independent neutral pressure measurements and other studies. These results establish HOMER as a high-speed diagnostic for spatially resolved visible edge emission, enabling plasma boundary detection and edge transport studies on MAST-U.