Sean Baker’s independent films feature protagonists you don’t normally see on screen: a Chinese delivery guy who sends money back home (Take Out), an elderly woman convinced she’s too old to drive to the store (Starlet), a Ghanaian immigrant who hawks designer knock-offs (Prince of Broadway). Baker’s latest, Tangerine, is about two transgender sex workers, Alexandra (Mya Taylor) and Sin-Dee (Kitana Kiki Rodriguez), who spend Christmas Eve hunting down Sin-Dee’s two-timing boyfriend on Santa Monica Boulevard. Though the stories sound like depressing social-realist works—in some ways that’s not entirely inaccurate—Baker’s work is infused with an infectious humor that brings out the best and worst in each character. Abuzz with positive reviews since its Sundance premiere, where it was revealed the film had been shot entirely on an iPhone 5s, Tangerine redefines contemporary American independent cinema. The film opens July 10 in New York.