During his six months sketching stars on Hollywood film sets in 1937-38, Snelling discovered the magical potentials of theatrical lighting. He tried avant-garde illuminations during his film 'exploitation' phase in Wellington 1938-40 and learned more about the technologies during his Sydney work with the Kriesler electronics factory in Newtown during World War II.
(During the war, Kriesler produced electronic parts for Mosquito plywood aeroplanes. Towards the end of the war, Snelling encouraged his employers to transfer their technologies into 1930s Streamline-styled, two-tone, bakelite radio cases. In his personal portfolio of work, there is a studio shot of a Kriesler radio which it is assumed he designed. The radio's style was notably more innovative than the styles of American radios which began to be sold in Australia after the end of the war.)
During his post-war design and architecture career, Snelling regularly included dramatic, often indirect, lighting features and systems in his interiors and gardens. These were designed to create moody atmospheres and deliver direct light to highlight specific objects or human tasks such as cooking or reading. Again, his lighting strategies were strongly influenced by Frank Lloyd Wright's early 20th century precedents.
His interior and garden lighting at the Arthur F. Little residence on Clareville's waterfront won him a distinction in the 1966 Awards of the Illuminating Engineering Society of New South Wales. Until that time, Australian-educated architects were mostly uneducated about either the technologies or artistry of theatrical lighting.