To document the scenes in quarantine wards, the crew had to, just like medical staff, wear protective clothing for hours. As a result, many of them suffered from swollen eyes.

"I will never forget that feeling of discomfort. But being in the same shoes as the doctors and patients helped us to bond with them during the filming process," said Fan.

Filming in the "red zone"– quarantine wards for infected patients in critical condition – was another memorable moment for Fan. He recalled doing a heartbreaking interview with a red zone nurse who recounted her emotions when the mobile phone of a patient who had suddenly died kept ringing while inside the bedside cabinet.

"Most patients were alone during the hospitalization. There were no family members around. The medics are with them all the time, and for some, until the end of their life journey," said Fan.

"We were impressed by the courage and determination of mankind to stick together and overcome obstacles," he added.

According to Ke Dingding, the director of photography, the team was met with logistical challenges as well. Among them was the need to adhere to the local prevention and control measures, which stipulated that their 4K cameras needed to undergo disinfection before they could be used in the red zone.

"We knew that the disinfecting process would damage the equipment. We then thought of protecting the cameras with a layer of plastic, but this would prevent us from operating them properly," said Ke.

The team eventually sought help from their colleagues in Shanghai and requested that several waterproof GoPro cameras were sent over to Wuhan.

Looking back at the experience, Fan said that he has been moved and inspired by some of the stories he learned.

He singled out the story of a 32-year-old doctor from a Shanghai hospital who was sent to help with intubation procedures in Wuhan.

"This doctor had broken up with his girlfriend of 10 years just before leaving for Wuhan. He told me that the job at hand helped him to get over the heartbreak because there was just no time to be feeling sad for himself," said Fan.

"Most importantly, doing what he did in Wuhan taught him to love life again."