Dr John Cam Duncan had no formal art training, but he was a friend of well-known painters Sydney Lough Thompson and Alfred Walsh. During the latter part of the First World War, he had access to the studios of Augustus John, William Orpen, and others in the United Kingdom. After his return to Aotearoa, he worked for the Health Department at the Bath House, Rotorua.
In 1931, he spent time with Aotearoa-born, Australian artist Elioth Gruner, who influenced him deeply. He won the Bledisloe Medal for best landscape in 1934. An oil titled The Lonely Lake was included in the 1940 National Centennial Exhibition of New Zealand Art in Te Whanganui-a-Tara. He showed with the Auckland Society of Arts. Other works are at Auckland Art Gallery Toi o Tāmaki and the Sarjeant Gallery Te Whare o Rehua.
