In “Detropia,” directors Heidi Ewing and Rachel Grady show that a once-vibrant Detroit is emptying. (Photo by Tony Hardmon)

Detropia,” the new documentary from “Jesus Camp” directors Heidi Ewing and Rachel Grady, is an impressionistic view of a once-vibrant, now-emptying Detroit. The film, which opens Friday at the District’s West End Cinema, depicts the Motor City as a ghost town whose blank-canvas vibe is more attractive to conceptual artists than blue-collar workers — or the manufacturing firms that might hire them.

This is not the portrait the filmmakers set out to draw. “We kind of thought we were doing a phoenix-from-the-ashes story,” says Grady via cellphone as she heads from New York, her current home, to the District, where she spent most of her childhood.

Ewing grew up outside Detroit, Grady says, and had long advocated making a film about the city. Its rebirth “is the story the mainstream press has been touting for years, and we thought that’s what was happening. Then we got there, and we realized that it was much more complicated than that.”

What the filmmakers found was a metropolis that had shrunk from 1.8 million inhabitants in 1950 to a little more than 700,000 in 2010. One family was departing every 20 minutes, and 40 of the city’s 139 square miles were essentially empty. Real unemployment was estimated at 50 percent.

Ewing and Grady filmed for more than a year. While they worked, Mayor Dave Bing (D) warned of possible bankruptcy and proposed requiring residents of little-populated neighborhoods to move to denser ones.

Of the partners’ original concept for the movie, Grady says: “You know, shame on us. We always tell people you can’t go in with a preconceived idea. You can have a loose theory, but don’t be dogmatic.”

The movie focuses on a few characters, including George McGregor, the president of United Auto Workers Local 22; Tommy Stevens, whose Raven Lounge presents old-school soul and blues; and Crystal Starr, a video blogger who explores and documents the city’s abundant ruins. Shown more glancingly are an arty young couple attracted by cheap lofts, Swiss tourists seeking picturesque decay and men who collect scrap metal from abandoned houses.

“We interviewed literally hundreds of people when we first got there — before we took out the camera,” Grady says. “Then, you just sort of sift through and end up including people who have a lot of distinct qualities so you’re not redundant in your storytelling.

“Also, it’s got to be entertaining,” she adds. “We felt like these people were fun to watch, fun to listen to.”

Storytelling, the director says, is less central to “Detropia” than it was to such previous Ewing and Grady efforts as “The Boys of Baraka” (about poor Baltimore boys sent to an experimental school in Kenya) and “12th and Delaware” (named for a Florida intersection where an abortion clinic faces a pro-life pregnancy center).

The partners began shooting without a narrative framework, Grady says. “Not only did we not have a structure, I don’t know if it has a structure now,” she says. “It’s a total departure for us. It’s more of a mood piece, a poem, a tapestry of the national climate.”

The film mentions Detroit’s reputation for arson but not its high crime rate. “We just went on the assumption that our audience knows that Detroit is dangerous,” Grady says. “Visually, we tried to hint at it, through some of our shots of empty streets and people creeping around, and some of the music. That this isn’t a normal place to live.”

One thread that holds “Detropia” together is, of all things, opera. The movie includes bits of several performances at the Detroit Opera House, as well as a scene in which an operatic singer tests the acoustics of the once-majestic but long-abandoned Michigan Central railroad station.

“It’s unexpected,” Grady says. “Which is something we look for. And we wanted to include a nod to the fact that there is still classical art in Detroit. One of the things that defines a city is great art institutions.

“And, also, there’s something operatic about the city itself.”

In addition, she says, “the people who go to the opera are wealthy suburbanites. We don’t really include them in the film. But we wanted to make sure you understand, on some level, that there’s still wealth there. It’s just circling the city.”

The contrast between city and surroundings that Grady observed in Detroit evoked her days in Washington. “Some things reminded me so much of D.C. A disenfranchised black population that never seemed to get a leg up, surrounded by extremely powerful and affluent white people in the suburbs. Corrupt mayors. Shaky political system. Lack of voice. Those are things that felt familiar to me.”

In the movie, Stevens predicts that “what happened in Detroit is now coming to you.” But Washington and other cities with white-collar economies are currently booming.

“Is the rest of urban America going to look exactly like Detroit? Probably not,” Grady says. “It has some unique features that made it especially vulnerable.”

But the filmmaker does see one possible parallel between Detroit and Washington. “I haven’t lived in D.C. in such a long time that I don’t know how these newcomers and the different generations are interacting with each other. But that’s a big problem I’ve seen in Detroit. The 50,000 new, college-educated kids who have moved to downtown Detroit don’t seem to have any relationship with the 650,000 African American Detroiters who are third-generation there. And in order to have a healthy metropolis, you need that.”

Jenkins is a freelance writer.

Rachel Grady will take questions after the 5 and 7 p.m. screenings of “Detropia” on Friday and Saturday at the West End Cinema.