The footage was later kept in the former Soviet Union and produced into color documentaries in Russian and Chinese, and released in both countries. However, the film released in China gradually aged.

Shanghai Audio-Visual Archives rediscovered the original footage preserved at the Russian State Film and Photo Archive-around 200 rolls of film, each lasting 10 minutes-and purchased the copyright of some cuts this year, according to Xie Shenzhao, chief director of New China in Color.

"The new documentary is based on these precious recordings," says Xie.

"We revisited some places and people seen in the footage, aiming to showcase both previous and modern life in Beijing, Shanghai, Guangzhou, Nanjing and Hangzhou to the audience."