Judging by the number of visitors turning up to see Underexposed at the Gallery of Photography, there is nothing more calculated to attract our attention than the intimation that we can see something that someone, somewhere, at some time, didn't want us to see. In fact, perhaps the only impulse stronger than the desire to see what shouldn't be seen is the desire to prevent it being seen. These competing instincts define the territory explored in this exhibition, compiled by Index on Censorship to mark the millennium.
It covers images under a variety of loose headings, including "Propaganda", "Culture", "The Body", "The Planet" and "Recovered Memory". Given the premise, the most surprising thing is how familiar many of the images are - including those of mourners tearing at the shroud of Ayatollah Khomeini, for example, or of Israeli nuclear scientist Mordechai Vanunu ingeniously imparting information to the world about his kidnap by Mossad. In fact, the exhibition consists not so much of images that were banned or suppressed per se, as images relating in various ways to contentious areas, images in some way implicated in the perennial business of the control of information and the meanings we are allowed to attach to it.
We've come a long way since Soviet workers busily, and to our eyes clumsily, doctored or simply obliterated photographic prints to document retrospectively Stalin's continual rewriting of history throughout the Terror. But it's not just a question of our own credulity in the face of editorial distortion, or of the increasing technical sophistication of digital manipulation - which can be used aggressively, as is demonstrated in the Evening Standard's spiteful alteration of an innocuous image of Labour's John Prescott. Beyond such considerations, there is also the realisation that the camera always lies, in the sense that the photographer is never apart, is always ideologically positioned, and the image is always, similarly, partial in both senses. We are caught in the paradoxical predicament, as Harold Evans puts it, of acknowledging "the power of the still image" and simultaneously distrusting it.
Though we might like to pretend we are above the fray, we too bring our preconceptions and value judgments to what we see. Even the best intentions of Index are not proof against this fact. There is a slightly annoying quality of self-righteousness, a moral smugness, to some of the captions in the show. There are some straightforwardly spine-chilling images in the exhibition, including a bizarre study of "cannibals" with "their cuts of human flesh" on the Volga in 1921, during a time of widespread famine, or a grotesque view of the executed Allen Lee Davis, who was electrocuted in, rather shockingly, 1999 in Florida. Ireland and Irish history feature in the form of British soldiers behind a barricade during the Easter Rising, and a group portrait of The Cairo Gang, the British intelligence agents hunted by Michael Collins's men during the War of Independence.
Apart from shocking content, though, often what is disturbing about an image is the fact that it doesn't conform to our expectations about what an image should be. That is, obligingly coherent, as organised by the intelligent eye of the photographer. Here, the photograph of an actress, Sonia Romanoff, smearing ice cream on the face of paparazzo Rino Barillari just doesn't seem to make any sense. It's impossible to figure out a "before" and an "after"; we just have these two people in an impossible physical configuration and a caption telling us what might be going on.
The same goes for a photograph of Joan Crawford getting to grips with an admirer at the Dorchester Hotel in 1956. Destined for a newspaper, it and the accompanying story were pulled. But was that because, as is implied, its grittiness contradicted the Hollywood publicity machine version of stars and fans? It might equally have been because the image is perplexing, almost surreal, like a frame from Un Chien Andalou by Luis Bunuel and Salvador Dali. What offends in this case is not the content of the image, but the form. It lacks a conventional narrative structure and, in a way, this lack reinforces its claim to authenticity.
Michael Arlen wrote once about the effect of seeing the television reporter Murray Safer unsettled and out of breath while delivering his report to camera from Vietnam in the mid-1960s. At a stroke, the entire edifice of official reassurance about the course of the war came tumbling down. What was alarming was not the information Safer conveyed but the fact that he was out of breath and nervously glancing over his shoulder. Photographers like Philip Jones Griffiths, Larry Burrows and Don McCullin famously had an astounding degree of access to operations during the Vietnam War and can claim to have had a real impact on public perceptions of the war and its eventual course. In this show, the image of the discomfiture of US Marines, caught unawares by the Tet Offensive in 1968, is a case in point.
The tight media management of the Falklands and Gulf Wars point to increasingly sophisticated news and information control on the part of the political establishment. Yet the problem now would seem to be not so much the suppression or manipulation of information as the sheer over-abundance of imagery and its concomitant devaluation as a medium of information. Jones Griffiths, writing as a working photographer, mentions the blurring of the boundaries in infotainment, something that has, as it happens, characterised the media year to an unprecedented extent since Index on Censorship originated this project. In a voyeuristic culture, we expect to see everything, but perhaps it will all mean less and less, and eventually we will believe anything and nothing.