Illuminatin' Sweeney features interviews with the artist, as well as excerpts from his early image-processing experiments. Sweeney's credo — "to make tapes as satisfying to me as listening to music" — is explored in short pieces that use the Moog Vidium process, which improvises and abstracts images using musical feedback. The concluding footage of his father's funeral heralds the more personal documentary approach that characterized his work in the 1980s.