Women of substance: Photographers are becoming just as interested in the physical form of their work as in the image itself. Marina Benjamin is impressed

Visual artists everywhere are rebelling against the physicality of their chosen medium. Film-makers are breaking the bonds of narrative sequence; multi-media and installation artists are busy dematerialising the art object; while photographers - masters of the surface - are pursuing the elusive third dimension in an exploration of sculptural depth, architectonic possibilities and cultish object-status.

The Photographers' Gallery has brought together the work of three Austrian artists under the banner 'Material World', a title that deliberately summons up notions of substance, presence, bulk and opacity. Here, some very deft handling of the third dimension takes place; images silk-screened onto lead or glass leant against the wall, unframed. Some are lit from behind, others are cut into circles, or lined up to overlap. Their contact with the wall is tenuous so that their physical presence is enhanced, but they haven't quite attained a free-standing existence of their own.

Aglaia Konrad has lined both sides of a corridor with large overlapping sheets of glass onto the backs of which images of urban scenes have been glued. Impersonal aerial shots of cityscapes alternate with close-ups of anonymous people or architectural details, mimicking the random way in which the eye alights upon unrelated urban happenings as you move through city spaces. Lit from behind, the glass sheets become windows on the world, implicating viewers in a play between reality and illusion, intimacy and alienation.

The physical world of Sabine Bitter panders to our gargantuan desire to bring the whole world within our grasp. Three glass discs from the series 'Globus' contain panoramic views of mountain scenery rolled up into 360-degree images that have been silk- screened onto the edges of the discs (above). Within these dark fuzzy borders, the sky forms luminous centres. Flat-earth theorists would have delighted in the easy sense of containment purveyed by these discs which contort nature into an impossible reality.

Eva Schlegel's search for materiality began with a chance find of glass-plate negatives in a hazardous wastebin. Schlegel silk-screened the amateur snapshots onto lead in such a way that they retain the barely-there essence of a negative image. The merest traces of human forms, trees and rocks echo the intangibility of the personal histories carried by the snapshots. Each of these leaden images constitute one half of a diptych: each is complemented by a sheet of plaster coated with scratched graphite. The deliberate abstract markings are symbolic positives representing the tangibility of the here and now as contrasted with the receding past from which the glass-plate negatives were excavated.

All the works in the exhibition mobilise a metaphor of tactility in order to establish a dialogue between the viewer and the viewed, between past and present, the concrete and the illusory. In themselves they transcend the photographic constraint of being merely pictures of something. By hovering between states of being, they are able to address the relationship between consciousness and the brute matter of the external world. As such they are less about the physical world than the metaphysical one - the eternal quest for the ghost in the machine.

'Material World' is at the Photographers' Gallery, 5 & 8 Great Newport Street, London WC2 (071-831 1772) to 1 Oct

(Photograph omitted)