The late spring in the Gobi Desert, northwestern China, is already scorching at noon. Yet in Cave 138 of the millennium-old Mogao Grottoes, a UNESCO World Heritage site in Dunhuang, Gansu
He is adjusting a camera for taking photos within the cave, where the murals are already blackened, leaving only several blue-black lines recognizable.
"How did it go?" He asks the same question every time he triggers the shutter.
The smoky murals are highly reflective, and the walls are uneven. Even though He has been photographing caves for nearly a decade, for him and his colleagues, getting a clear picture is still a challenge.
He says he was called to do the job by the Mogao Grottoes themselves. In 2013, the Dunhuang Academy was recruiting technicians to digitalize the grottoes. Though a layman in photography, He, deeply obsessed with Dunhuang culture, volunteered to join and worked diligently to hone his skills.
Each buddha in the murals is different, and so is the way to photograph them. To He, every shot is a new attempt and challenge.
The idea of digitalizing Dunhuang culture was first put forward in the late 1980s. The subsequent decades have seen much development and numerous achievements in digital preservation.
The "Digital Dunhuang" website, launched in 2016, has employed massive data resources, such as photos, video clips, archive materials and 360-degree views of 200-plus Mogao Grotto caves. As of last year, the database, which is available in both Chinese and English, had seen more than 16.8 million visits from users in over 70 countries, all free of charge.
From film cameras to high-resolution digital cameras, Dunhuang Academy has formed a set of key technologies and workflows suitable for the digitalization of grottoes.
"Although technologies are updating, we still face new technical difficulties every day," noted Ding Xiaosheng, deputy director of the institute of cultural relics digitalization of the Dunhuang Academy.
Built between the 4th and 14th centuries, the Mogao Grottoes are home to a vast collection of Buddhist artworks, with more than 2,000 colored sculptures and 45,000 square meters of murals located in 735 caves, carved along the cliffs by ancient worshippers. Each of the caves is unique in size, shape and style, and so the shooting strategy for each cave is distinct.
"We have to try repeatedly to make sure that the color and light of each photo is consistent. A minor mistake will affect the overall work," He said, adding that often only a dozen photos can be kept after a whole day's shooting.
He has photographed about 20 caves over the past decade. The caves are freezing inside, even in summer, and the photographers often have to work wrapped in down jackets and knee pads.
To He, they are following the footsteps of the older generations.
"Image collection is only the first step. We must do it steadily to keep it going," he said. "Most of my colleagues are young people, and whenever there's a difficulty, we should take the initiative to seek solutions like our predecessors. Only in this way can we live up to the spirit of Mogao."
