He risked his life to leave a "historical record of our martyrdom."
In September 1939, the Nazis invaded Poland. By April 1940, the gates closed on the Lodz Ghetto, the second largest in the country after Warsaw.
Throughout the war, over 210,000 people would be imprisoned in Lodz.
Among those held captive was Henryk Ross. He was a Jewish sports photographer before the Nazi invasion and worked for the the ghetto's Department of Statistics during the war. As part of his official job, he took identification photos of the prisoners and propaganda shots of Lodz' textile and leather factories.