SOGO Department Store, Causeway Bay, Hong Kong — Light Box Retrofit

At SOGO department store in Causeway Bay, Hong Kong, this project retrofitted an illuminated advertising light box whose original light guide plate — in service for more than three years and manufactured in Europe — had failed and needed replacement. The retrofit replaced the light guide plate with an LED backlit panel system. Two light-diffusion film thicknesses, 39mm and 45mm, were tested side by side to compare light quality. Both held a measured illuminance of 2790 lux, but only the 45mm film was confirmed free of visible spot shadows, giving a smoother, more even light across the panel face. The work also covered the light box's structural frame (documented as the "A2" light box structure) and ceiling-mounted lamp panels sized at 245mm, alongside a photographed installation sequence from bare frame through to finished, illuminated panel. Paired before-and-after night photography and lux readings recorded the shift from a dim, damaged light box to an evenly lit, shadow-free LED display — an improvement verified through direct, side-by-side testing rather than a single untested spec change. **Products used**: LED backlit panel system; light guide plate replacement; 39mm and 45mm light-diffusion film (tested comparatively); "A2" light box structural frame; 245mm-panel ceiling lamps.