Superconductor-based cameras that can detect a single photon—the smallest smidgeon of light—have existed for 20 years, but they’ve remained confined to laboratories due to the inability to scale them past a few pixels. Now, a team at the National Institute of Standards and Technology (NIST) in Boulder, Colo., has created a 0.4-megapixel single-photon camera—400 times as large as the previous biggest camera of its type.