Via FastCo Design:
At the Museum of Math, 45 of Brand’s specular holograms have been installed on a metal matrix along one gallery wall. Visitors can use an array of overhead lamps to make the looping knots and patterns move as light cascades over the surfaces in multiple directions. Our rods and cones are telling us that we’re seeing a 3-D image. Turns out, we’re seeing 2-D pieces of metal that Brand has engraved with millions of tiny pinpoints, each engineered with its own curvature that reflects light in a specific way.
Brand calls the process zintaglio, and he discovered it one night after playing a set at a blues club in Chicago. He took off his glasses to rub his eyes, and suddenly noticed that the club’s holiday tinsel produced a different image in each eye. He began trying to prototype metal objects that would take advantage of the effect in a controlled way. “It occurred to me that the optics I wanted should be carved out of metals and plastics, but, it turned out, at the time even high-end CNC machines were not sufficiently fast and precise,” he writes. “However, thanks to Moore’s law, a few years later, that obstacle was gone.” Today, he makes the holograms out of small pieces of metal. Most of the software, he tells Co.Design, “is home-brew with some open-source visualization tools thrown in.”