Mary Ellen Mark was a fearless documentary photographer who lived to capture the raw realities of life among homeless teenage street hustlers in Seattle, residents of a psychiatric ward in a state institution in Oregon, prostitutes in India, numerous sets of twins, and members of the circus. She was also a Visionaire contributor on issues like Beauty, Game and Bible. She spent her career and life making humanist, and relatable images of outsiders and subcultural. On Monday the innovative image-maker died in Manhattan age 75 from Myelodysplastic syndrome which is a blood disorder.

Mark was a pioneer of her generation. Born March 20, 1940 in a Philadelphia suburb, she made her first pictures, with a Kodak Brownie camera. But what set her apart from her peers was her enthusiasm and passion; these traits would end up taking her into some of the most obscure communities throughout the world.

After graduating from the University of Pennsylvania where she earned a bachelor’s degree in painting and art history in 1962 and a master’s degree in photojournalism in 1964, Mark won a Fulbright scholarship to photograph in Turkey. This was the start of her long career and the beginnings of her interest in capturing those who lived differently and in difficult sometimes-heartbreaking circumstances. “I’m a documentary photographer,” she told Bomb magazine in 1989. She was particularly interested in the work of documentarians like Henri Cartier-Bresson, Robert Frank and Dorothea Lange and these photographers continued to inspire her throughout her life.

An assignment in 1983 to shoot a story about runaway kids for Life magazine led to the work that defines her career, and which she would continue making for the next 35 years.

The assignment was to take place in Seattle, which was then considered one of the most livable cities in the country. Mark photographed kids smoking cigarettes, fighting, dumpster diving and breaking into buildings. Shining a insight into these kids lives and what they have learned in order to survive.

“Reality is so bizarre, you could never think of those ideas. Fiction writers are great in the sense that they can imagine. I could never ‘imagine’ things. What I’m really great at is looking, that’s my forte, to be able to pull things from reality, to see what’s strange and real.”

Most of her assignments where from magazines like Vogue, National Geographic and Vanity Fair to name a few. She was chosen for her ability to translate her documentary ethos into editorial stories.

Telling these raw visual stories for mainstream audiences established some of the most unexpected and memorable works of her life. She showed a remarkable ability to win the confidence of her subjects, and she maintained contact with many of them through the years. This trust enabled her to convey very personal images reflecting a truthful reality.

“I remember the first time I went out on the street to shoot pictures,” she told the magazine Communication Arts in 1997. “I was in downtown Philadelphia and I just took a walk and started making contact with people and photographing them, and I thought: ‘I love this. This is what I want to do forever.’ There was never another question.”

In the 1990s Mark made the transition to fashion photography and portraiture, with ad campaigns for clients like Coach, Eileen Fisher and Heineken she still however continued with her documentary work.

Throughout her career, Mark, married to the director Martin Bell, who survives her, and with whom she made many films, including an accompaniment to the Seattle work, also called Streetwise and nominated for an Academy Award, shot production stills for movie sets—Catch-22, Apocalypse Now, Satyricon, and most recently, in 2008, Baz Luhrmann’s Australia.

In 2014, she was given the Lifetime Achievement in Photography Award from George Eastman House. “I would die if I had to be confined,” Ms. Mark told an interviewer for the introduction to “Passport.” “I don’t want to feel that I’m missing out on experiencing as much as I can. For me, experiencing is knowing people all over the world and being able to photograph.”

Her latest book, “Tiny: Streetwise Revisited,” returns to the main character in the book “Streetwise,” one of several homeless Seattle youths she photographed in the early 1980s. The book is set to be published by Aperture in the fall.

Mark photographed primarily in black and white, she was known for being fierce, and difficult, and a fighter for her work. This drive Paid off when you see the impressive body of work she has now left behind.