(CNN)The Lunar New Year is the only time of year China's army of migrant workers gets to go home. Known as "chunyun," the annual travel crush is the world's largest migration of humans. The lengths workers go to to see their families during the country's biggest holiday, which this year began February 19, is one facet of migrant worker life captured by factory hand turned photographer, Zhan Youbing. For more than a decade, Zhan was himself one of China's 250-million strong "floating population" of migrant workers. Originally from the rural, inland province of Hubei, he worked as a security guard in the factories that surround the southern boom town of Guangzhou, over a thousand kilometers away.
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Zhan Youbing is a former factory worker, now an acclaimed photographer
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Zhan uses his intimate knowledge of migrant workers to capture their lives on and off the assembly line
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"I have lived this life," he says. "So I know exactly what their situations are"
If photography meant self-fulfillment for @placeholder in the early days, it is now more of a mission.