Video artist Nam June Paik's "Zen for Film" (1964) is a projection of clear film leader. The image changes over time as dust and imperfections become visible. From the Bard Graduate Center gallery:
Inherent in the work's material and conceptual aspects are notions of chance, trace, changeability, boredom, silence, and nothingness. With Zen for Film, the projection of a film leader creates an image of apparent nothingness that oscillates between the immateriality of projected light and the material traces, which slowly obliterate the leader's transparent surface. Zen for Film shares meaningful aspects of chance, silence, and nothingness with such works as composer John Cage's 4"33" (1952) and artist Robert Rauschenberg's White Painting (1951).