Minute but significant happenings: Bill Viola, The Passions, National Gallery, London

Brief jumbled notes from a very packed and intensely exhausting yet invigorating exhibition...

'Silent Mountain' (2001), a double screen of a woman and a man dressed in plain blue tops facing the camera. In Viola-slow-mo they come to life and painful but silent howling overcomes them both as they writhe in synchronised agony. Ouch ouch ouch.

'Four Hands' (2001), a black and white polyptych on four LCD flat panels was mesmerising: four hands of different physical ages moving together in different expressions, seemingly in a slow dance. Gorgeous. A visual banquet.

The National Gallery is the right space for this exhibition with Viola drawing upon old masters paintings and devotional images.

Viola makes the viewer a proactive figure in his work. The absence of camera movement combined with trademark slow motion forces the viewer to focus in on the minute details of the characters in the often decontextualised, narrativeless films. Time passes in a very strange way: that's as accurate a description as I can manage. Facial expressions, movement of bodies, hands, clothes, water, fire are all up for close, detailed examination. Light changes imperceptibly. The slow motion is so slow the viewer cannot anticipate what is to happen next; the viewer is forced to concentrate so keenly on the image in order not to miss the momentary minute but significant happenings. It's both a draining and exciting experience. Wonderful. Definitely a run-home-skipping day!