These solo expeditions afforded her the opportunity to see New York's colorful inhabitants and scenery up close. Though parts of the city were very dangerous, Dorothea soon developed the ability to look at others without drawing attention to herself. Because she was "never obviously there," she could watch them without attracting harm to herself. This ability, as well as her lack of fear, would later enable Dorothea to become one of the world's finest documentary photographers. .
During visits to her mother's library, Dorothea realized her love of pictures. She spent hours poring through books of photography and art and hung copies of her favorite pictures on the walls of her bedroom. Dorothea was enchanted by art of all types and recalled having a religious-like experience seeing dancer Isadora Duncan perform in 1908. Duncan's ability to "electrify thousands of people at once" showed Dorothea that great art had the capacity to evoke strong emotional responses and move people to action (Meltzer, 14). .
Auspiciously, Dorothea's first job made her an assistant to famous photographer Arnold Genthe (renowned for his photographs of the San Francisco earthquake of 1906). Genthe encouraged Dorothea's photographic ambitions and taught her everything from lighting to printing to posing subjects. He also told her that in his life as a photographer he never had a dull moment, which was enough to fortify Dorothea's determination to enter the occupation. Within a year, she dropped out of the teacher's college and found a job as a portrait photographer for an upscale studio on Third Avenue. .
Contented in her new occupation but bored with her surroundings, Dorothea decided to leave home. Along with a childhood friend, she traveled west, stopping in New Orleans, Louisiana; El Paso, Texas; and Los Angeles, California. She finally settled in San Francisco, California. There, Dorothea not only took on a new name--adopting her mother's maiden name "Lange" and dropping Nutzhorn--but began a new life.