In the 1980s Ackling produced a body of work that harnessed sunlight as his medium. Using a small glass lens the artist focussed the rays of the sun so that they burnt into wood, bone or card. Although he recognised the parallels between his work and that of the early photographers who used sun to develop images onto chemically treated papers, Ackling regarded his work as being in harmony with nature, and that followed in the American Indian tradition of using fire and smoke to carry messages across vast distances.