His on-site service was cheaper than photo studios in town, and soon people were lining up.
Zheng says that the recognition of his work was a source of relief.
After he managed to save some money, he started to set aside time to travel across the country and train his lens on the stunning landscapes and interesting people he met along the way.
In 1984, a photo capturing a bunch of art students sketching on the banks of the Huangpu River in Shanghai received a special award at a national instant art photography contest hosted by the Shanghai Photographer's Association.
"I consider it my first step into the realm of photographic art," he says.
The award also earned him a position at a cultural organization in Lin'an in 1986, and from there he went on to serve the district's Disabled Persons' Federation, the Lin'an Literature and Art Federation and finally the local photographers association.
In 2001, he wanted to do something special to commemorate Beijing winning the bid to host the 2008 Summer Olympics.
"I was working at the disabled persons' federation, so I came up with the idea of photographing 100 athletes with physical challenges," he says.