Denis Villeneuve, the French-Canadian director whose drug cartel thriller “Sicario” opens Sept. 18, says that film and his previous, “Prisoners” — both shot by Roger Deakins —“belong to the same cinematic alphabet. Both movies wanted to embrace nature.”

“For ‘Prisoners,’ we were embracing the idea of shooting during Thanksgiving in the fall, that kind of depressing, dark light. And ‘Sicario’ is the opposite; we went for the harsh, brutal light of the Chihuahua Desert (in Mexico) — very harsh, very cruel sunlight.”

Villeneuve adds that both features deal with “a naturalistic approach, and a kind of minimalism visually,” which happen to be Deakins’ stock in trade.

If the d.p. can do without artificial light, or f/x, for that matter, all the better. What he can capture on camera is what he prefers to see onscreen. That’s not to say he won’t use whatever tools are necessary. On “Sicario,” like “Prisoners,” he went with the digital camera of the moment, the Arri Alexa. And on a particularly harrowing scene where a U.S. task force raids an underground tunnel used to smuggle drugs, he and Villeneuve used two different night-vision attachments employed by the military — one an infrared thermal system.

“You have to have some kind of light, even if it is very minimal,” Deakins says. “It was almost ridiculous how little light I was using, but I didn’t want to go too far and make the image look too good, because, naturalistically, it wouldn’t work.”

The scene is a perfect example of a director and his d.p. going for a heightened realism, while also delivering a bravura sequence visually.

Shooting at the border and in certain parts of Mexico on “Sicario” certainly posed problems, especially in Ciudad Juarez, a city mired in drug violence and countless murders over the past couple of decades. And when a shootout at the El Paso/Juarez border was called for, impossible to do due to security reasons, the filmmakers created the Bridge of Americas on a parking lot in Albuquerque.

“We had the same problem on ‘No Country for Old Men,’” says Deakins about the 2007 Coen brothers movie, “we created (the border) on an overpass.”

But capturing the verisimilitude of Mexico was important, especially in a convoy sequence to arrest a high-ranking cartel member, in which Mexico City’s sprawling suburbs double for Juarez. “Denis and I thought, ‘this has to be another world,’ it’s key to Emily’s (Blunt) character,” says Deakins. “It’s got to be totally alien to her experience.

“Mexico City is like an urban monster,” adds Villeneuve. “I was looking for specific things. The scouts found places in Mexico City that were really close to the reality of Juarez: the wide streets, those shopping centers, the architecture, the poverty.”

Although Villeneuve says he was “born in 35mm,” using the Arri Alexa brings “a sensibility that 35mm film doesn’t have. But with Roger he approached digital like 35; it means everything is done on camera, on the set. Color timing for Roger is a very small process. It’s something more crude in some ways. At the end of the day, it’s not about the camera, it’s who’s behind the camera. And it’s Roger Deakins, who could shoot with a shoe and it would look great.”

Villeneuve will be working again with Deakins on a “Blade Runner” sequel, which neither of them could talk much about. Harrison Ford will reprise his role as the bounty hunter of the title from the 1982 original, also notable for the work of the late d.p. Jordan Cronenweth.

Deakins has always wanted to shoot a science-fiction movie, despite his experience filming “1984” 30 years ago with director Michael Radford. He doesn’t plan on referencing Cronenweth’s work on the original. “The way a film looks comes from the script and the director’s interpretation,” he says. “Obviously Jordan’s work stands by itself.”

And, for Villeneuve, Deakins stands by himself. “With Roger, every single shot is crucial and unique,” says the director. “He has the pressure of being Roger Deakins on every shot. He brings a strong poetry to the image, but in a very natural way.”