Ansel Elgort, left, and Shailene Woodley in a scene from "The Fault In Our Stars." (AP Photo/20th Century Fox, James Bridges) Ansel Elgort, left, and Shailene Woodley in a scene from “The Fault In Our Stars.” (James Bridges/ Associated Press via 20th Century Fox, James Bridges)

“I enjoy looking at beautiful people,” Augustus Waters (Ansel Elgort) tells Hazel Grace Lancaster (Shailene Woodley) when the two teenagers meet at a support group for cancer survivors at the beginning of “The Fault In Our Stars,” the adaptation of John Green’s wildly popular young adult novel.

This bold statement begins their tender, too-short love affair, but it is also the beginning of a real problem for “The Fault In Our Stars.” Hazel, a precocious, terminally ill teenager, insists at the beginning of the film that, unlike sanitized versions of cancer stories, “This is the truth. Sorry.” But it is a truth that is subject to Hollywood norms in a way that saps some of the power from the story and from Hazel’s claim to honesty, and illustrates the limitations of mainstream movies in telling certain kinds of stories.

Most predictably, “The Fault In Our Stars” shares Augustus’s fondness for beautiful people. Elgort and Woodley share a dewy, young-star splendor that changes little even as their cancers wax and wane. Their friend Isaac (Nat Wolff) has a dorky cool to him, as if the studio system developed an improved model building off the example of Christopher Mintz-Plasse.

When Hazel and Gus chat outside their support group, we see a survivor with a shaved head and a heavier teenager pass behind them and out of the focus of the shot, the physical realities of cancer and the variation of humanity confined firmly to the background.

Director Josh Boone extends the same treatment to Hazel’s memories of her illness, which began when she was 13. Her gasps for breath, the experience of having her head shaved and a moment in an intensive-care unit when Hazel’s parents (a very fine Laura Dern and Sam Trammell) give her permission to let go are all shot in soft focus and sometimes in slow motion. That same effect returns to the film in a contemporary arc in the story when Hazel’s lungs fill with fluid again. In the hospital, the voice of one of Hazel’s doctors even fades out when he talks about her prognosis.

(It was around this point in the movie that I made a note to keep an eye out to see whether it would rain during a trip Hazel and Gus take to Amsterdam to seek out their favorite author. Spoiler alert: It does not. Our heroes’ epic journey, and our stars’ magnificent hair, must be spared these little inconveniences.)

This gauzy approach to Hazel’s illness does serve one purpose. When Augustus’s cancer returns, and his health begins a steady decline, he calls Hazel from a gas station late one night, gravely ill and very frightened. It turns out he has what appears to be a badly infected kidney stent, and he is vomiting bile and blood.

For once, “The Fault In Our Stars” does not retreat into fuzziness or include a stent only at the edge of a shot, and the scene is shocking and upsetting. But by this point in the film, “The Fault In Our Stars” had already made me somewhat skeptical of Hazel’s claims to radical truth-telling, or the oft-repeated mantra from her favorite book that “pain demands to be felt.” It may make that demand, but Hollywood is determined to deliver a heavy dose of pain relief in the name of prettiness.

I understand that it sounds like I might be demanding some sort of pornography of suffering. The treatment of cancer is not the only place in the film where Hollywood practice eats away at the story, though.

Take the questions of class and money. Hazel’s family home, for example, meets mainstream movie standards: capacious and equipped with a hood range in the kitchen to juice our real estate envy. Hazel texts Augustus on her iPhone and e-mails a favorite author on her MacBook Air. On the trip to Amsterdam, Hazel’s mother gives her a Halston Heritage dress to wear to dinner. These details are absolutely standard for a blockbuster film. But they also produce a bit of cognitive dissonance when Hazel’s mother initially tells her “We don’t have the money” to go to Europe.

These are little things, of course. Movie studios and directors have become accustomed to our willingness to smooth over these discrepancies in our minds, just as we accept that broke young people can afford fabulous Manhattan and Los Angeles apartments, or that Katherine Heigl has trouble attracting suitable male attention.

This is fine when we are purchasing shares in a fantasy. But when a movie makes a claim for honesty and importance, as I think “The Fault In Our Stars” does, is it so much to demand that a Hollywood production actually try to reach beyond the aspirational mission that undergirds so much filmmaking?

John Green is certainly not responsible for these failures, nor is Woodley, who adds another impressive credit to her resume as Hazel. There is a lot that crackles and pops here, including a marvelously scabrous Willem Dafoe. But the places where “The Fault In Our Stars” falls prey to convention and condescension offers a sharp reminder that the page can be a more three-dimensional place than the screen.