The notion of a domestically-based ‘ethnological study’ dates at least from Montesquieu’s Lettres persanes. But what distinguishes this attempt by Rouch and the sociologist Edgar Morin to ‘bottle’ the climate of Paris circa 1960 is their camera’s candid assumption of its own disruptively active presence: interviewees are introduced to each other, form groups, and may well (in one case) have got married after shooting was over. In an interesting epilogue, Rouch invites them all to comment on his footage.