James Deen and Lindsay Lohan star in “The Canyons.” (IFC Films/IFC FILMS)

A leitmotif runs through “The Canyons,” a folie-a-trois involving writer Bret Easton Ellis, director Paul Schrader and actress Lindsay Lohan, having to do with the end of cinema. The shoestring-budget movie opens with a bleak, de-saturated montage of decrepit movie theaters, images that reappear with every chapter heading throughout the story about a group of young bottom feeders trolling the outer margins of Hollywood’s indie film industry.

“The Canyons,” which was notoriously rejected by festivals and distributors only to end up available on video on demand this week, doesn’t nearly live up to its elegiac imagery. Nor does it reward the hype surrounding Lohan’s co-star, the porn actor James Deen, Schrader’s strenuous attempt to gin up interest by filming an orgy scene in the nude, and other intimations of material much too naughty for polite company. The far duller truth is that “The Canyons” presages not the end of cinema but its soft, white underbelly: Bad movies will always get made, it assures us, as long as there are people with dumb money, an eye for stunt casting and gift for ballyhoo at its most cynically Barnum-esque.

Lohan plays Tara, whom we meet idly thumbing her iPhone while her boyfriend, a movie financier named Christian (Deen), brags about their sex life to a wholesome looking couple. Those clean-cut kids are Gina (Amanda Brooks), Christian’s assistant, and her boyfriend Ryan (Nolan Funk), who has just been cast in the movie Christian is bankrolling, largely at Tara’s suggestion. After some stilted conversation over a restaurant dinner table, Christian and Tara retire to his Malibu dream house, where they proceed to invite a young man — whom Christian has thoughtfully procured on the Internet — to watch as they engage in sex.

So that happens. So does some other stuff, having to do with deception, indiscreet texts, betrayals and random acts of back-stabbing. In fact, “The Canyons” often plays like the Dirk Diggler-Amber Waves version of “Mean Girls,” the teen comedy Lohan starred in almost 10 years ago which, from the looks of her sallow, haggard face, might as well be a century. It’s possible to catch fleeting glimpses of that incandescent young girl who seemed so full of promise during her Disney days — the cowlick at her hairline, the barely perceptible freckle on her upper lip — before Schrader returns to the freak show he promised, usually involving a topless scene or lingering shot of Lohan’s painfully collagen-ed pout.

The strangest thing about “The Canyons,” though, is that Lohan is the best thing in it. Schrader does his best to infuse the movie with both the noir moodiness of “Taxi Driver” (which he wrote) and the frisson of erotica, but instead the film comes off as little more than a lazy, amateurish diversion. (One recommended parlor game is to catch the continuity errors.) If viewers didn’t know his and Ellis’s pedigrees, they might think it was a reasonably accomplished USC student film. The sexual sequences aren’t nearly as edgy or graphic as the filmmakers would lead us to believe: They give the audience all the lethargic seediness of porn and none of the pleasure.

But Lohan, mirabile dictu, delivers a genuine performance in “The Canyons,” bringing naturalistic honesty and disarming vulnerability to a role that deserves neither. Just as you can still see that girlish cowlick, you can see the talent that makes such early films as “Freaky Friday” and “Confessions of a Teenage Drama Queen” so much fun to watch. The kid had it, and she can still bring it, whether she’s called upon to cry on cue or act remotely interested when she’s rolling around in bed with three other people under a revolving constellation of disco lights (just another Tuesday night in the ’Bu!). There’s a moment in that simultaneously tame and tawdry scene when Lohan catches the camera’s eye and looks straight into it. It’s supposed to be a subversive moment, full of confrontational brio. But from here, it just looks like “Save me.”

Unrated. Contains profanity, violence, drug material, smoking, nudity and graphic sexuality. 95 minutes. Available on Amazon Instant, iTunes, Xbox and on-demand cable starting Aug. 2.