A retrospective at Tate St Ives can be a poisoned chalice for the major artist. It postpones his or her prospect of a showing at Tate Britain by a couple of decades, and can appear to consign them to the comfort zone of "Cornish Art": the heritage Modernism of Barbara and Ben, Terry Frost, Patrick Heron et al, stuff we love (well, most of us) because it reminds us of being on holiday, but may feel, in our heart of hearts, to be more than a touch minor. On the positive side, Peter Lanyon, who was killed in a gliding accident in 1964, isn’t around to mind, and there’s something to be said for being able to look from one of his lyrical canvases straight out at the surf crashing on Porthmeor Beach and the edge of the windswept, ancient landscape Lanyon regarded as his personal Calvary.