Stereographs are pairs of photographs that represent what is seen by the left and right eyes. When viewed through a lens-based device called a stereoscope, the pair seems to resolve into a single three-dimensional image. Stereoscopic cameras had short focal lengths and thus short exposure times, allowing the capture of “instantaneous views,” as they were described in the 1850s and 1860s. Pedestrians and moving vehicles appear in sharp detail in these stereographs, which also exploit the dimensional effects of Paris’s boulevards.