Otto Heinz Mack (*1931, Hesse) is a German sculptor and painter and co-founder of the influential, international ZERO Group. Mack became known for his experimental reliefs of light as well as his light installations in the desert, which are counted as some of the earliest examples of Land Art. He is a multiple documenta participant and represented Germany at the Venice Biennale in 1970.
Mack's art is characterized by ceaseless experimentation with material, light, and movement. In addition to dynamic and structured paintings, he has created numerous sculptural works, such as vibrating light reliefs, monumental light stelae, or cubes reflecting light. Starting in 1958, he created one of his preliminary rotors, in which elements are moved via small motors. Ever since, movement has played a central role in his work, alongside light, making him one of the central representatives of Kinetic Art.