In a scene from The Vow, Rachel McAdams and Channing Tatum park by the Chicago waterfront, strip down to their underwear, and scamper into the lake for a frigid late-night dip. But the lake is Ontario, not Michigan. The couple is cavorting on Cherry Beach in McAdams’s home city of Toronto, and the skyline is visible—minus the CN Tower. Canadian locales routinely impersonate American cities in Hollywood movies, but what’s striking about The Vow is how blithely it shows familiar glimpses of a city that’s supposed to be incognito. The lovers first cross paths at City Hall, and exchange their vows at a guerrilla wedding staged in the Art Gallery of Ontario. The movie is punctuated by postcard vistas of the real Chicago, but whenever the actors are in the shot, Toronto backdrops shatter the illusion, at least for anyone who knows the city.

There’s nothing wrong with faking locations. It’s something Hollywood has always done and always will. Movies, after all, are in the business of make-believe. But after so many years, the routine casting of Toronto and Vancouver for American burgs has become irksome, especially now that these cities have more personality and profile of their own. Ontario film commissioner Donna Zuchlinski claims local audiences enjoy spotting their hometown onscreen—“it adds to the movie-going experience, that sense of pride.” But stripped of its character, a surrogate city exudes blandness. In a confection like The Vow, despite a spirited performance from McAdams, that cavalier lack of authenticity penetrates deep into the bones of the movie, from the generic characters to the formulaic script. It seems to say: what the hell, the audience will never notice.

When American studios shoot movies north of the border, would it kill them to set one there? That almost never happens. Although Canada is the only country in the world that’s lumped into Hollywood’s domestic market, apparently we’re not domestic enough to be a place where people would actually live. “Americans want to see American cities,” says Toronto production designer Sandra Kybartas, a veteran of both Canadian and U.S. shoots. “They have a limited palate for exoticism.”

Despite the rising strength of the loonie, U.S. production is booming north of the border, attracted by diverse locations, skilled crews and tax credits. Last year, Ontario hosted $413 million in foreign production, up 30 per cent from the previous year. Toronto is often cast as Chicago—even Chicago, the Oscar-winning musical, was shot here. The Vow’s production designer, Kalina Ivanov, says the two cities look alike because “they’re both from the same era and they’re both on lakes.” Kybartas, who spent years dressing Toronto as Chicago for TV’s Due South, disagrees: “It’s hard to get Toronto to look like Chicago, because Chicago has all the power lines buried.” But U.S. productions “generally do a good job,” she adds. “They’re very careful in eliminating the CN Tower and catching the iconic bits.”

Yet incongruities do pop up. The most ridiculous case was Jackie Chan’s Rumble in the Bronx (1995), in which Vancouver’s mountains loomed behind New York City. But even last year’s 50/50—a credible cancer comedy starring Joseph Gordon-Levitt and Seth Rogen—has absurd moments. Shot in Vancouver and set in Seattle, 50/50 shows Adam (Gordon-Levitt) in Vancouver’s Stanley Park, lamenting, “I’ve never been to f–king Canada.” In another scene, he jogs along the seawall and ends up at Seattle’s Space Needle. “Long run,” he sighs.

Why not just set 50/50 in Rogen’s hometown of Vancouver? “The marketing people at the studios prefer to set American stories in American cities,” says Shawn Williamson of Brightlight Pictures, one of 50/50’s producers. “There’s a perception that it matters to American audiences. I don’t think Canadian or international audiences care where a film is set.”

Two recent U.S. productions driven by Canadian talent actually did set stories in Toronto—Chloe, directed by Atom Egoyan, and Scott Pilgrim vs. the World, starring Michael Cera. Sadly, both bombed. Toronto’s stardom will just have to wait.