The first retrospective of the late German artist’s five decade career, “Walter Giers: Electronic Art” opens at ZKM Karlsruhe. Initially producing kinetic and op art, Giers began referring to his works as elektronische spielobjekte (electronic playthings) in 1974. The show offers a broad survey of his light and sound sculptures, and his signature exposed circuits (image: Kunst Macht Nature, 1979), which let viewers get up close and personal with the materiality of electronics.