TORONTO -- Matthew McConaughey calls Quebec filmmaker Jean-Marc Vallee extremely "dexterous," adding that he was surprised by the director's ability to depict 1980s-era Texas in "Dallas Buyers Club."

Premiering at the Toronto International Film Festival, the movie tells the story of Ron Woodroof, a real-life heterosexual electrician/rodeo rider who learned he was HIV-positive and subsequently smuggled AIDS drugs from Mexico.

Over the years, Vallee has chosen wildly diverse projects, from the auspicious coming-of-age tale "C.R.A.Z.Y." (of which McConaughey was a fan) to the lavish period piece "The Young Victoria" and the dreamy "Cafe de Flore."

But even the Texas-raised McConaughey wondered how Vallee would tackle the Lone Star State, adding that an outsider can have a sentimentalized view of something they're not familiar with.

"He didn't, like, romanticize it, but I thought he'd be a little intimidated about getting a sense of place," McConaughey, 43, said during an interview Sunday at the festival.

"He didn't know Dallas, Texas, in 1986, he sure as hell didn't know rodeo ... but he's got a dexterity that he was able to get there ... (and) figure it out."

For his part, Vallee said he relishes challenges from one film to the next and immersed himself in British culture as he was preparing for "The Young Victoria."

"We've got to do our job, you know, we've got be close to the people we're trying to depict in their world and learn to love them and be part of them ... And I had a good teacher ... a Texas class 101 from Matthew McConaughey, and he did a great job."

While McConaughey has recently been branching out from his typical rom-com roles with edgier films like "Magic Mike" and "Killer Joe," "Dallas Buyers Club" takes that transition one step further.

The actor is virtually unrecognizable as the emaciated Woodroof, who starts off as a hard-partying homophobe and ultimately becomes a champion for HIV sufferers and their right to choose their own drugs.

There's already Oscar buzz around McConaughey's performance, as well as that of Jared Leto as a drag queen who goes into business with Woodroof. Jennifer Garner rounds out the cast as a compassionate doctor.

McConaughey said he connected with Vallee so well that they once sent each other simultaneous emails musing on the same piece of dialogue.

"That's when you go, 'We're making the same movie,"' said McConaughey, snapping his fingers.

"He's now hearing my voice, we're getting on the same page ... and that allows me to get any defences down."

The Toronto International Film Festival runs until Sept. 15.

"Dallas Buyers Club" is set for release this fall.