In an unusual 15th century Renaissance painting titled The Healing of Deacon Justinian by Fra Angelico, a miraculous tale of transformation is told. Two saints, Cosmas and Damian, take the leg of a recently deceased Ethiopian man and sew it to the sleeping Deacon, whose own diseased leg has been amputated.

For decades, the Moroccan multimedia artist Mounir Fatmi has been fascinated by it. In his latest exploration of the painting, The Blinding Light, which is on show at Paris Photo, he has created an eerie series of images which overlay Angelico's original work with photographs shot in modern, hi-tech emergency rooms during real operations. Through the fusion of manipulated layers, critical details intertwine - it is as if the present-day doctors are attending to the deacon himself.

"The transparency between the two images creates a new dimension - it's neither present nor past," says Fatmi. "In the original painting the miracle is about God and religion, and in my photography it's about science. So here we have science and religion running in parallel."

There are three prints in Fatmi's series (and one on a mirrored surface), each doctored differently. In one, the deacon is black-skinned while his new leg is white, reversing the racial relationship of the original painting.

Fatmi's work is indicative of a palpable trend for transmuted imagery at this year's Paris Photo. At almost every turn, these peculiar visions seem to eclipse their straighter, more traditional photographic counterparts. "Since the beginning of photography, all photographic imagery is manipulated in one sense or another," Fatmi argues. "I think that images are created to be manipulated. Over time the image becomes something else."

Works by Dorothee Golz, including Prada Girl (right)

The work of Dorothee Golz certainly attests to this. The German artist has sought and photographed young women who resemble, in attitude as much as looks, iconic figures from classical paintings, such as Raphael's Madonna and Vermeer's Girl With A Pearl Earring. The subjects have been photographed in locations which are quintessentially contemporary, their clothes are unmistakably à la mode and yet because the faces from the paintings, which have been superimposed on to them, are so intense and so recognisable, the viewer is momentarily confounded. These images trigger a double-take from many passers-by, who must wonder whether the women from the paintings have been liberated by the transformation.

Aquarium 07 by Zhou Hongbin

Elsewhere, the desire to cook reality has been channeled towards diverse subject matter ranging from the whimsical (a tank of rabbits swimming by Zhou Hongbin) to the serious (the repurposing of colonial archival material by Yee I-Lann) via the vivid floral portraits of French photographer Valérie Belin. Anna Vogel's haunting pictures of owls - made by stripping away clarity and colour from existing photographs - reinforce the power of manipulated works to enthrall, especially when contrasted with Roni Horn's matter-of-fact owl portraits nearby which are not nearly as startling. Horn's depictions are too familiar; Vogel's creations look more like apparitions.

But there are two artists whose fabricated works have been capturing the attention of the crowds in Paris more than any others: Du Zhenjun and Yang Yongliang. Zhenjun's vast montages portray mountains of chaos. They appear to be dystopian predictions of the collapse of civilisation in the distant future, and yet they are built entirely of current realities. From a sea of brawling humans to a sprawling mass of pollution, the message is bluntly apocalyptic. Just metres away is the piece by Yongliang from the series called The Moonlight which also seems to presage the future, albeit with less foreboding. His imaginary cityscape is composed of skyscraper upon skyscraper, great peaks of them, in a never-ending metropolis. Compiled using images of existing tower blocks, this huge backlit image sparkles. It is a beautiful, if overwhelming, vision.

Pollution, from the Babel series, by Du Zhenjun

Manipulation is not always so complex. There is a black and white image at the heart of the exhibition, taken by Rodney Graham, of a leafless oak tree; it is neatly shot and of imposing scale, but is otherwise unremarkable. However, having been turned 180 degrees to stand on its branches, it is altogether more intriguing. It echoes the inverted reality seen on the ground glass screen of a large or medium format camera. And it encapsulates the sensation that Paris Photo is at its most daring and distinctive when photographic realities are literally or metaphorically tipped upside down.