One day I was walking with a female friend in Tehran when she was pulled away by the police and held in one of their offices for a few hours. Her crime? She wasn’t wearing the proper hijab — the head scarf that, in some interpretations of Islam, women must wear whenever they are in the presence of men who are not close relatives. In Iran , the government insists that all women wear it.

My friend was told to ask a friend or relative to bring the proper hijab for her to wear. Until it arrived, she could not leave. She told me that I shouldn’t just take photographs of wars, but that I should document what Iranians were experiencing in public life in a big city like Tehran. She inspired me to do this project.

From last April through September, I photographed about 20 women who agreed to participate. They were from a variety of social classes. Some voluntarily wore the hijab, others wore it only because it was required. The wearing of the hijab is enforced in part by a volunteer citizens’ militia, the Basij , as well as what are called the “guidance” police. They roam the popular streets of Tehran and other Iranian cities, monitoring religious observance.