When he was a child, Pasang Tharchin would stare for hours at the crowds of mountaineers who would pass through his hometown as they were preparing to master earth's greatest challenge: Mt. Qomolangma.

As an adult, he helped blaze a trail for China's first documentary recording the trek from base camp to summit.

Slim, with dark red cheeks kissed by the cold, Pasang, 36, was born to a poor herding family with six brothers and sisters in Xigaz, southwest China's Tibet Autonomous Region. It's location near the base of Mt.Qomolangma, also known as Mt. Everest in the West, meant it was often used as a starting point for climbers.

"The job opportunities are limited here," Pasang said in fractured Mandarin. "So I went to the Tibetan Mountaineering School to be trained as a professional climber."

After graduating in 2003, he began working as a mountain guide, specializing in repairing and maintaining ropes along the slope and setting up camps for climbers. He has reached the top of the world's tallest mountain nine times.

Despite more than a decade of working in the mountain, he still never imagined he would become part of a film crew to shoot China's first documentary capturing the climb to the top.

The documentary "Himalaya: Ladder to Paradise" turns its lens on the mountain guides. Its title plays on the name given to the patterns on the palisades across the Tibetan plateau. The Tibetan people believe the ladders lead to the Holy Land.

Pasang and other guides were selected to help shoot the film, as most professional videographers lack the skills and endurance to shoot in the harsh conditions higher than 5,000 meters above sea level.

While filming began in 2013, chief director of photography Tashi Wangyel chose Pasang to help record the last leg of the climb 7,028 meters above sea level due to his contribution during the 2008 Olympic torch relay at Mt. Qomolangma.

After four months of film training, Pasang and fellow guides were dispatched to finish the documentary in 2014.

According to Tashi, the most suitable time for climbing the peak of Mt. Qomolangma is a three day window ranging from March to May each year. The crew waited at base camp for three months before the opportunity presented itself.

After collecting and analyzing data provided by China Meteorological Administration and the meteorological bureau of Tibetan Autonomous Region, Pasang and his partner set off before dawn on May 25, 2014.

Severe cold brought extreme difficulties for filming along the slope.

"The filming devices weigh more than five kilograms," Tashi said. "The Tibetan cameraman carried more than 10 kilograms of camera gear, plus an oxygen bottle and thermal gear."

Keeping batteries charged and in working condition, while trying to capturing difficult time lapses along the steep and glazed slope were two other challenges that made the task almost impossible, Tashi said.

But the two Tibetan cameramen would spend six hours a day recording the starry sky, capturing the change between light and dark above the peak.

The air at their base camp, at 5,200 meters, had only half the oxygen than at sea-level. The higher they got, the more rare it became.

"I could hear my heart beat clearly," Pasang recalled. "I was constantly out of breath."

"As we reached 8,000 meters, we put the camera onto the ground and pushed it forward it."

After six hours, Pasang and his partner became the first two Chinese cameramen to bring a tripod to the peak of the Mt. Qomolangma, where they finished filming.

They stayed on the top of the mountain for 20 minutes and captured precious images from the roof of the world.

Still, Pasang was not confident and worried about the video's quality.

"He even felt ashamed and stopped at 6,000 meters on the way back," Tashi said. "He refused to return to camp at 5,200 meters."

The movie's assistant director and the chief cameraman went to persuade him to return.

"When the video was played at the camp, we found it was good enough." Tashi said, though he admits there are flaws.

"The control of focus, the stability of the lens, the variety of the scenery and the lack of brightness were still not satisfactory in the final version," Tashi said.

Despite rough edges, "Himalaya: Ladder to Paradise" has crested the 6 million yuan (about 945,000 U.S. dollars) mark since it was released nationwide in mid-October.

"It is successful enough under the pressure of domestic and foreign commercial movies," Tashi said. He believes the movie will achieve the highest attendance among Chinese documentaries.

The film's crew was also the first in the industry to capture aerial footage above an altitude of 6,500 meters.

"Some of the scenery shots were finished by our crew, who also took risks," said Tashi.

During a windstorm, the chief cameraman had his glasses blown off his face. He slid eight meters down the slope, unable to see.

"If it were not for the tent of another mountaineering team, he would have fallen into a chasm," Tashi recalled.

The documentary was also purchased by BBC and NHK for screening overseas. The production team has also finished post-edits on a five-episode television series, though Tashi did not reveal the release date.

The experience gave Pasang a taste of filming and has inspired him to begin shooting on his own. "It changed my life," he said.

Editor: Ellen Liu