A bank of lights

Since summer, the night skies of Bogota have been illuminated by a light show that plays across the exterior of the Banco Colpratria Tower, a 46-story building in the Colombian capital (pictured). "The bank has wanted illumination for many years, but ran into too many problems with traditional HMI equipment," reports engineer Christian Perrotti. "There was no room to install fixtures on the ground, and the investment in light fittings was too expensive."