Bianca Stigter’s recent documentary Three Minutes: A Lengthening is based on a short home movie taken by an American tourist in the Polish town of Nasielsk in 1938. The same section of film appears again and again, accompanied by commentary and testimonies, slowed down, zoomed in on and freeze-framed. Yet these everyday images of Jewish life acquire an extraordinary poignancy because we know that almost everyone on screen will soon be caught up and killed in the Holocaust. Something of the same spirit pervades Philip Hoy’s striking essay-length book M Degas Steps Out. When he went to an exhibition about...