Warhol: A Celebration of Life... and Death  National Gallery Complex, Edinburgh, until 7 October  Andy Warhol would have been 80 next summer. His soup cans and Brillo boxes, Jackies and Elvises are nearly half a century old. They have lost none of their graphic force, but what about their original content? What has time done to an art based on images that were once so familiar anyone could 'recognise them in a split second in the street', as Warhol said, but which are now instantly recognisable only as Warhols?  Take this huge show in Edinburgh - A Celebration of Life... and Death, as it is portentously titled. There are a good many works here that can have no split-second factor at all. How many visitors under 20 will recognise the numerous pictures of Grace Jones, say, or Keith Haring or Nico? Can anyone spot the venerable Man Ray? And Del Monte's peach halves may still be global business, but Mott's apple juice? Did it make it over here? Who has ever heard of Eighties DJ Juan Dubose?  Dubose and the juice crates are now meaningless as icons of themselves, and I'm guessing that few enough people dine daily on Campbell's soup (as Warhol always did) that the gigantic cans currently wrapping the pillars of the building outside are only a semi-successful promotion. But what all this obsolete imagery reveals, in a sense, is just how much of an old master Warhol has become, how enduring the look and power of his art. Dubose may be unfamiliar, but the hot shimmer of his body, black on blood-red and haloed in a solar glow, declares what a star he once was: a star burned out, dead of Aids a few years after this sombre painting.  The celebration of life, not death, is a trickier proposition for this show to put over, given that practically all of the portraits commemorate the dead and whole galleries are given over to the car crashes, suicides and skulls. But the point is well made; Warhol loved the design of the Campbell's cans, the serpentine flash of the dollar sign, adored the twin stars of the Empire State Building and the Statue of Liberty. You were to relish the red, white and blue of the Brillo boxes (themselves designed by a painter) with their evocative address - Brooklyn NY - printed as if on a letter.  Of course, you were also to ponder the fact that they appeared indistinguishable from the real thing - art could no longer be defined solely in terms of visual criteria - and that everyone could and did own something exactly like this. That they are priceless today, and now look so very evidently handpainted, probably goes against the spirit in which they were made (and sold, at $5 a pop).  The Brillo boxes date from 1964, and the standard claim is that Warhol's best works were all made between the late Fifties and Valerie Solanas's attempt to kill him in 1968. This show contains a large tranche of later works loaned by Anthony d'Offay, Warhol's London dealer, that don't counter that claim - guns and burgers, ads for paratroopers' boots, Liberty wanly reprised, all set against miles of high-chrome US camouflage that suggest weary scepticism, if not joyless line-extension. But the Mao paintings, the hammers and sickles, all of the death's head self-portraits and more were made after he had recovered from the bullet.  As the years recede, death does seem to be Warhol's subject: his forte. He painted Liz Taylor when she was dangerously ill and her face is fading fast into mist. Truman Capote, his eyes blue as heaven, is nothing but soul and cigarette. Warhol's gods and goddesses are all gone. Elvis, literally printed on a silver screen, appears twice like double vision, both of himselves a blur. Marilyn loses her definition, just held on the verge of dissolution by a few final touches like make-up.  Suicidal Marilyn, widowed Jackie, grieving face growing darker like her funeral shadow until it becomes a pictogram of pure pain, the terrible car crashes where you scan the multiple image trying to find the body beneath the tyres. It isn't true that repetition deadens the emotions. The more you try to decipher these grainy screenprints the more you fear to look, dreading what you might find. There is the shattered car. Then the driver dangling from a telegraph pole barely visible in the flames and then, last and nearly worst, a man in white jeans walking insouciantly by. On suffering they were never wrong, the Old Masters.  The room of skulls is brilliantly installed: ice-white wallpaper, the skulls in pistachio, pink and tutti-frutti; it looks like some nightmare version of a children's nursery, and sure enough the shadows cast at a certain angle by these old bones look exactly like infant skulls. Lurking among them is Warhol himself, looking remarkably bright, if not right at home here, a skull like a pet monkey on his shoulder.  A whole lower floor is devoted to Warhol's drawings, photographs and time capsules, and they give a greater sense of his character than any show I've seen. The sheer camp of his early commercial drawings - pouting boys, dandy clothes - prefigures so much of the deadpan humour of his films and books, and there is an unexpected nostalgia in the capsules into which he presses every fragment of his life and times.  But even the children's paintings, very rarely shown, of spacemen and police cars, clockwork mice and drumming pandas, have a minatory tone: dangerous and strange, as if liable to explode. An overlay of buzzing yellow or a lightning strike of orange can give a frightening charge to the most innocent of toys.  You can cut Warhol many ways, make of him a history painter or a radical portraitist, a philosopher or a cold parodist. An exhibition of nothing but his late portraits of zillionaires, from German industrialists to Conrad Black in his prime, would certain reveal him as the latter. This show does not want to admit that he idolised celebrity, or skimmed the shallows of the mass media, though both form distinct strains in his art. But its overall selectiveness gives a much deeper, graver Warhol than before, a Warhol who has long since passed the test of time.  Tate Liverpool, until 23 September  First lifetime retrospective for the British godfather of Pop.  Fermoy Gallery, King's Lynn and Oxburgh Hall, Norfolk, until 18 August  Two-site show for this tremendous Chinese installation artist.  Kenneth Martin & Mary Martin Camden Arts Centre, London, until 16 September  Order and chance, movement and rest - mobiles, drawings and paintings by the British Constructionist couple.
Art: Half a century on, many of Andy Warhol's iconic images may have lost their original pop culture references, says Laura Cumming, but his style and vision leaves his legacy looking more assured than ever.