British *Op and *Kinetic artist, born in London. He had no formal artistic training and until 1959 he worked as an assistant in various architectural practices. He then joined the RAF and was discharged with ignominy in 1960. He began to paint in 1963, influenced by Bridget *Riley, with whom in 1968 he set up S.P.A.C.E. (Space Provision, Artistic, Cultural and Educational), a scheme for providing studio space for young artists. In 1967 Sedgley began to incorporate lights in his work, for example in his ‘video-rotors’—painted rotating discs on which a variety of electronically programmed light patterns were played. From about 1970 he has experimented with combining sound with colour; often he works on a large scale, creating environments in which spectator movement triggers photoelectric cells, causing colours to change.