The ghetto in Lodz, Poland, was one of hundreds created by the Nazis across Europe, used to temporarily separate Jews from the rest of the population. Most residents would be sent to killing centers, if disease or starvation did not kill them first. The Lodz Ghetto is now the subject of a photography exhibit at the Museum of Fine Arts in Boston. Called "Memory Unearthed," it features photos by Henryk Ross, a Polish Jew who lived inside the ghetto, and who buried his negatives in order to protect them from the Nazis. Chip Reid reports on the photographer who used his camera as a weapon of resistance.