“We usually use light to illuminate things,” James Turrell has said. “I am interested in the ‘thingness’ of light itself.” Associated with the 1960s Light and Space movement, Turrell is globally renowned for his examinations of optics. His newest exhibition, at Gagosian’s Le Bourget gallery, features two new large-scale installations—one from his ongoing “Ganzfeld” series, which envelops the viewer in a shower of color, and one from his mixed-media “Wedgework” series, which focuses on depth and how it is perceived. The show also features six new smaller pieces from Turrell’s “Glassworks” series of in-wall installations. Taken together, it’s a quintessential slice of Turrell. —Lucy Horowitz