Charles Gaines: Multiples of Nature, Trees and Faces; Hardeep Sahota: Bhangra Lexicon – review Laura Cumming The visions of the California artist Charles Gaines (b.1944) are as glorious as they are rigorously principled. He takes vast monochrome photographs of what is inherently beautiful – the human face, the spreading boughs of a tree – and then mounts them behind Plexiglas screens. Each screen is partially overpainted with tiny coloured squares, and each pixel bears a number. It is the strangest configuration to behold. Gaines is about as renowned in America as a sys...