Carrying a bamboo basket on his back, Wang Zhongqing saluted to the camera, the little finger on his right hand deformed after decades of toil.

Wang, a veteran soldier in northwest China's Shaanxi province, died earlier this year at the age of 90. But his image lives on in a photo taken by photographer Chen Xiaojun.

A photo exhibition, titled "Glory, Image: I Am a Veteran Soldier", is being held at the National Science Library. Opening last Sunday, it will last until October 7. The 50 photos exhibited were selected from albums by Chen Xiaojun and Ren Hui, who spent a year travelling across China to take pictures of nearly 100 veteran soldiers.

The idea of taking photos for veterans started more than a year ago when Chen saw a notice seeking photographers in Nanjing, capital of east China's Jiangsu province. Although he didn't make the trip, the notice inspired him.

"They are getting old and leaving us," he said. "But they should never be forgotten. We need to race against time to preserve their images."

He soon embarked on the journey to look for veteran soldiers with his friend Ren Hui.

The first soldier they found was Wang Zhongqing. "He was an old man in dire need of help," Chen was told by a volunteer from a veteran charity.

They then climbed over the mountains to reach Wang's shanty. "It was a rainy day," Chen recalled. "We trudged for five or six kilometers on the winding and muddy paths before finding him deep in the mountains."

Wang was then at the terminal stage of nasopharyngeal cancer and living in poverty. "He carried eggs with a bamboo basket to go out of the mountains every half a month, earning about 20 yuan (3.1 US dollars) in the market of a nearby township," Chen said bitterly.

Deeply touched, he took a photo on the mountain road, while Wang was saluting - perhaps for the last time in his life.

Seven of the 50 veteran soldiers whose photos were on exhibition have passed away, including Lu Shaochen, 93.

Lu was an interpreter who joined the army in 1943 and fought in Burma. According to his last request, his children will put his portrait in front of the television Thursday morning, assuming the man can watch the military parade in heaven.

Most veteran soldiers--pilots, tank drivers, riflemen and interpreters--were saluting in the photos, but there are exceptions.

Dong Jimin, 111, joined the army in 1931, when northeast China was taken by the Japanese. In the photo, he is wearing a white shirt, his left hand held close to the ear as if he was trying to hear something.

Yang Qusai, 87, was sick in bed while his photo was taken. A driver, he regularly made trips on Burma Road, a lifeline that linked the Chinese battlefield with allied forces during World War II.

Zhao Zhenying, 98, witnessed the surrender of the Japanese in Nanjing, then capital of China's Nationalist government. He was head of a guard battalion during the ceremony. In his photo he is wearing a T-shirt with the numbers "1945-2015", behind him lay a photo of his deceased wife.

Last month, Xue Gang, curator of the exhibition, took Zhao to Chang'an Avenue where the anniversary parade will take place. "Do you remember where were you 70 years ago?" Xue asked him.

Zhao thought for a while and shook his head. "I forget," he murmured.

"Three years ago, Zhao could talk on and on about the past," Xue recalls.