Multispectral LED Sphere, August 2017
Christos Kampouris Husheng Deng Alix Feniès Abhijeet Ghosh
Imperial College London
Fig. 1: Realistic Graphics & Imaging group’s multispectral LED sphere consisting of 168 RGB and white (W+) LED lamps. The LED sphere can be employed for controlled appearance measurements as well as realistic lighting reproduction.
Abstract: We have built a multispectral light stage (LED sphere) consisting of 168 RGB and color temperature controllable white (W+) lamps, respectively. The light stage is powered with off-the-shelf programmable MR16 lamps from Philips Colorkinetics: 168 iColor MR gen3 lamps for RGB illumination, and 168 iW MR gen3 lamps for color temperature controllable white (2700K – 5700K) illumination. The design is heavily inspired by various light stages developed by Paul Debevec and colleagues at USC-ICT, particularly Light Stages 3, 5 and X. However, unlike a typical geodesic (subdivided icosahedron) structure, our light stage metal (steel) structure (2.5 meter diameter) has been fabricated along spherical coordinates with latitude-longitude profiles for a simplified wiring and Ethernet-based control layout for the LED lamps. The light stage can be employed for both controlled appearance measurements as well as realistic lighting reproduction applications.