Jacob Riis may have set his house on fire twice, and himself aflame once, as he perfected the new 19th-century flash photography technique, but when the magnesium powder erupted with a white, blinding light, he illuminated some of the darkest corners of Manhattan’s impoverished tenements. Despite the journalist now mostly being remembered for his photography of turn-of-the-century New York City, he only considered himself an amateur, a “photographer after a fashion.”