With Baltazar Kormakur’s star-studded “Everest,” which opens Sept. 18, looming on the horizon, moviegoers are likely to be treated to not one but two films that finally promise to capture the life-or-death stakes, not to mention the seemingly impossible physical odds, of extreme alpine climbing that Jon Krakauer chronicled so rivetingly in his bestselling book “Into Thin Air.”

The other film is “Meru,” the Sundance Audience Award-winning documentary that Music Box Films is releasing on August 14, and in which Krakauer appears. “Meru” documents the two separate attempts — in 2008 and 2011 — to scale the Shark’s Fin peak on Mount Meru in the Indian Himalayas. What sets “Meru” apart from “Everest” is its first-person perspective, having been co-directed and shot by one of the expeditions’ three climbers, Jimmy Chin.

“I think the filmmaking achievement was what was shot in the mountains; that’s never been seen before,” says “Meru” co-director Chai Vasarhelyi, who met Chin in 2012; they eventually married. “We’ve seen excellent mountain climbing films, but they’re all reenactments. The cameras (used) on ‘Meru’ were not fancy, but it works, and it’s authentic.”

According to Chin — a notable photographer whose work has appeared on the cover of National Geographic, and one of the few people to ski Mount Everest from the summit — he used first-generation handicams for that failed first ascent, which ended 150 meters short of the summit after a protracted storm depleted their rations. “They were very rudimentary,” he explains about the Panasonic Lumix and Sony Handicam the team used in 2008.

“And then between 2008 and 2011, the DSLR (digital single-lens reflex camera) video revolution happened and the 5D (Panasonic TM900) came out where you were able to shoot with much more cinematic quality-type footage at high def. I’m also a photographer so I used that camera both for shooting stills while I was shooting video.”

Since Shark’s Fin, at almost 22,000 feet (versus Everest’s 29,000 feet), is by many accounts the most technically difficult, and perilous, peak in the Himalayas, climbing and shooting simultaneously was no small feat.

“There are two threads happening in your head,” explains Chin. “That is the climbing, which requires most of your bandwidth, then there’s the filmmaking. The basic rule we set for ourselves was to not let the shooting affect the climbing, because the climbing objective was really the priority.

“We tried to shoot whenever we could,” Chins adds, “which wasn’t that much, because we are very busy doing other things. We also didn’t have the battery power, or storage, so we had to be very thoughtful of how much we shot (but to have) enough for the editor to work with.”

Chin’s fellow climbers are among the world’s foremost adventurists: Conrad Anker, a captain of the North Face climbing team who located legendary explorer George Mallory’s body on Everest in 1999; and Renan Ozturk, a fearless climber known for his video dispatches from the world’s most remote locales, who also acted as the doc’s co-d.p.

But it’s Krakauer who may be the film’s secret weapon. “He’s actually climbed with Conrad and Jimmy and Mugs (Terrance Stump) and Alex (Lowe),” says Vasarhelyi. “Jon also happens to be incredibly articulate. He’s not only a very well-known author, he’s also one of the foremost climbing historians. It’s also convenient that he has this wonderful penchant for drama.”