Blue Remembered Hills

Can hallucination invade the spheres of pure reason?

- Baudelaire

In 1922 Henry Ford rebuilt his home to recreate the one he had lived in 60 years earlier. As a gesture, it's a little too clunky to be described as an incursion into hyper-reality, but in its attempt both to recreate and to bypass the real, it makes an interesting precursor. Ford's endeavour to evoke an idealised image of a particular time is echoed, albeit more self-consciously, in the work of Stephen Murphy. But Murphy's take on memory is less nostalgic and perhaps a little more confused than Ford's: he attempts to complicate, to animate and, at times, to eradicate time as a place or a space that can be encompassed by a single frame or reference.

In the 15 images that comprise Untitled (1994), Tupperware litters a lawn, a sunbed waits expectantly in a garden and an abandoned pram sits in a deserted shopping arcade. What would otherwise resemble banal family snaps seem, because of their utter emptiness and lack of human presence, to be the spooky record of some indescribable crime. They give you an inkling of what it might have been like to climb aboard the deserted Marie Celeste, to see the dinners still warm upon the table, the chairs pushed hastily back, and no one around to eat, or to sail the boat.

Scanning photographs taken by family and friends into a computer, Murphy dropped the people down a digital black hole, leaving only the haunted detritus of their presence - what he calls, 'the unconscious images of irrelevant details' - to grace the final reprint of the photograph. With a deceptively simple gesture he demonstrates how new technologies have expanded not only our ability to see what is around us, but also, given how deeply we now seem to depend on photographs as aide-memoires, opened up the possibilities of manipulating memory itself. Funnily enough, with these works he anticipated a market that has proved enormously popular with the recently divorced and adulterous - now companies offer to alter photographs digitally to suit the story of your choice ('bring the incriminating photo to the Boots Instant Imaging Counter and we'll help save your blushes... your other half need never see the other half...'). But then photography has never been innocent.

In two early works from 1992, Self-Portrait as a Rabbit and Self-Portrait as a Dog, Murphy began his (often hilarious) examination of the nebulous space that hovers between the real and the imaginary. These mocking self-portraits look like a fusion of 19th-century freak-show posters and a set of perverse identity cards. They are as wilfully self-effacing, or misleading, as they are a deeper indication of what might constitute personality - just a little more absurd and complicated than the contours of your face.

This interest in images that embrace the counterfeit, the indecisive or the collapsed, is chillingly distilled in Bavaria (1996), a work made in collaboration with Don Brown. Unless you know it well, Bavaria is one of those places whose name immediately evokes a generalised image - a mechanically sublime place suffused with Gothic, Grimm-like intimations of gloom, a place of dodgy politics where nature was built from the twin fictions of 19th-century Romanticism and 20th-century misreadings.

Constructing the image was a complicated process. A composite sketch, sourced from various images (from George Lucas to Caspar David Friedrich) was turned into a 3-D model on a computer, which was then built, photographed, scanned back into a computer, retouched and output onto film. The result, an enormous, eerily hyper-real image of a non-place that looks like an amalgam of a hundred wintry landscapes you imagine you've seen but can't quite remember where, was pasted onto a billboard outside the Hayward Gallery in London. Appropriately, it ended up freezing onto the surface it was fixed to. But despite the technical complexity of its production and the Baudrillardian nod at the slippage between an idea and its translation, the most interesting element of Bavaria is its confounding beauty - confounding because ultimately there's nothing dumber than a generalisation. Which just goes to show that however many tools we have at our fingertips, it's still impossible to give an ideal form without it being complicated by another crucial element - the person looking at it.

Murphy delights in creating and imploding archetypal and generic images. It is as if every observation he has ever made is capable of being compressed into a single, distilled statement about the way we fuse the imaginary with the material world, however inadvertently. Murphy and Brown also created a series of generic digital images of submarines and missiles. In large colour photographs, they're shown doing what they're meant to do - flying through the blue sky or floating in a submerged gloom. Look at these photographs long enough, and the air or water becomes a vast colour field across which the object of destruction traverses like a blob of paint on a canvas. At once illusionistic and familiar (but how many people have actually seen an air-to-air missile or a nuclear submarine?) it's almost impossible to tell that they are models and not the real thing. Like the replicants in Blade Runner, digital technologies draw from the memories of every medium except their own, but can't help but develop an individual identity along the way. The result is images that often seem to be more about a state of mind than an actual location - a twilight place, where what you see is about to be transformed or transported into something or somewhere else. A brightly lit passenger ship glides into the night, storm clouds gather over a castle, or a moon begins to climb over a silhouetted dome - these are images that mine corny cinematic tropes while refusing to exhaust themselves, or the audience, by relying on anything so straightforward as a narrative or a denouement.

In his most recent exhibition at the Showroom in London, Murphy showed two companion films - Untitled (Butterflies) and Untitled (Red Dots), (both 1997). Initially the two works seem like entirely separate exercises, but repeated viewing reveals how their seemingly antithetical images feed off each other. Butterflies showed the faux-innocence of an idyllic, idealised summer landscape - a gentle curving river, distant hills, fields thick with wildflowers, comfortable clouds, sunny but not glaringly so - the kind of place your parents should have taken you when you were a kid. Hundreds of butterflies flit towards you and wheel away at the last second, as if they've just noticed your presence. It's a mesmerising, peaceful scene. But after a minute or two, you begin to realise that something's not quite right. Remember the Night of the Living Dead? You begin to feel suspicious and curious. A certain conformity, a schematic approach to 'the natural' increasingly makes itself felt. The cloudy blue hills look a bit too seamless, the flight of the butterflies just a fraction too jerky - as if they're marionettes. And then, most peculiarly, you begin to anticipate their flight path. Over and over they flutter back to exactly the same spot. Watch this film for too long and your thinking runs amok. You start to wonder - what is the idea of butterflies?

Red Dots presents, unsurprisingly, two large red dots that swing towards each other, join up, separate and swing apart again. They're hypnotic, almost nightmarish - like the sinister, swinging watch of a giant hypnotist. Luckily, the red of the balls keeps you alert to the vague possibility of danger. After a few minutes you begin to realise that the movement of the red dots mirrors the separation and unity of the butterflies' flight paths. A little later you start to notice that Red Dots, which originally seemed to be the more conventionally abstract of the two pieces, is just as much a quotation as the clichéd image of a summer's day. Dots? They're everywhere. Both films are cogs in an infinite wheel of appropriation, but seen together, they manage to create something entirely mesmerising out of a vocabulary that by now should have been bled dry.

On Murphy's desk I spotted a book called The Algorithmic Beauty of Plants. It explores, in a sombre and oddly surreal way, how an understanding of mathematics can facilitate the rendering of nature. It made me wonder how I ever found a mechanistic approach to visualising the world dry or unimaginative. Who's to say reduction can't be fluid, expansive? Who's to say a machine isn't as natural as a blade of grass? Who's to say one person's temporal space isn't someone else's conceptual one? Murphy's work makes evident the art in artifice - and makes it clear that artifice is only a problem when it pretends to be simply the sum of its parts. At the end of the day, if the moonlight prompts you to burst into song, who cares if it's fake?