The albino boy dressed in filthy, torn clothes leans over, resting one hand on legs so thin they look as if they could snap, the other clutching an empty corned beef tin. He was one among 800 starving children in an old school building in the secessionist state of Biafra, in southeastern Nigeria, visited in 1970 by the famous British war photographer Don McCullin.
The memory of this boy - who took McCullin's hand while he was talking to a doctor - haunts the photographer to this day. "I thought it was possibly the one moment in my life when I could have cried, publicly cried. And I thought, 'I hope this boy goes away and leaves me alone' because I didn't do this to (him)," he said, referring to the humanitarian consequences of a conflict that led to the deaths of some 1 million civilians from fighting and famine.
The black-and-white photo of the boy is featured in a major retrospective of McCullin's work at the annual international photojournalism festival in the French city of Perpignan, Visa pour l'Image, which runs through to September 15. The show spans his career, from images of dead soldiers in the Vietnam war to portraits of poverty in England, and more recently, its landscapes.
McCullin gave up war photography in the 1980s, apart from a trip to Syria late last year, and is painfully honest about the personal impact of the horrors he witnessed. At a panel discussion on photographing war last week, he spoke extensively of "the shame of memory".
"Once I started putting my hands into the blood of suffering and war, I became very disillusioned," he said. "I would stand in front of men who were going to be executed in front of me, who were crying, looking at me and hoping I could stop their murder. And there were dying children in Africa, who were starving. I would come to a feeding centre and they would think - ah, there is a white man, he's going to bring some food aid. All I brought to those children was a Nikon camera round my neck."
The lively discussion between four renowned photographers and the American picture editor John G. Morris tackled the issue of whether war photography makes a difference to those who suffer. The no-nonsense David Douglas Duncan, who became a combat photographer with the U.S. Marine Corps and is famous for his images of the Korean and Vietnam conflicts, said he could not think of one photograph that had ever changed a war. "We are photographers, not philosophers, first and foremost," said the 97-year-old.
Morris, who worked with the great names of 20th century photography, including Robert Capa, during a career that spanned Life magazine, the Magnum agency, the New York Times and more, disagreed with his colleague. He argued that iconic pictures from the Vietnam war, such as the picture of a naked girl running from a napalm attack, did have an influence. "They made people realise how futile the war was," he said.
Patrick Chauvel, the French photojournalist who has covered more than 20 conflicts around the world, asserted that "engaged photography" has the power to shake up people - including politicians - to shift their views, and ultimately to bring something to those struggling on the ground. "We are not going to stop war, but we can change things on an individual basis," he said.
Chauvel, who has sustained shrapnel and other wounds while on the job, spoke passionately of the role of war photographers in witnessing events - a duty that should be passed from one generation to the next, he asserted. "War has been around for as long as the world, but photographs stop people saying 'I didn't know what was happening'," he said. "We inform people, and they can accept or reject what they see, but at least they have been warned."
The discussion of the potential for photojournalists to shape the course of events resonated far beyond this particular debate, as the festival's Visa d'Or prize for news was awarded to photographer Laurent Van der Stockt for his work in Syria. He filed an in-depth report in May from a rebel-held suburb of Damascus with the journalist Jean-Philippe Rémy for Le Monde newspaper, which was instrumental in exposing the use of chemical weapons in the Syrian conflict.
Van der Stockt, who was also affected by nerve gas symptoms for a few days, told a separate discussion in Perpignan about Syria that he and Rémy had also decided to carry physical samples to be tested outside the country because they wanted "to bring back the truth and evidence that shows the truth" - an act that has provoked some criticism of them for crossing traditional journalistic boundaries.
"(Journalism) influences public opinion, and public opinion pushes the leaders of this world to go in a certain direction. This is a lot of blah-blah, but there are people dying, it's a massacre there, and it shows that it's an important job," the modest Van der Stockt was quoted as saying at the awards ceremony by the British Journal of Photography.
While an international response to the use of chemical weapons in Syria is still being hammered out, in this case at least it seems that journalists and their cameras can be more than neutral observers, and that their work can have a profound impact.
This, Chauvel said at the war photography debate, is something that those being photographed are increasingly aware of. Fighters on the front line, for example, are very aware of the effect images of them can have elsewhere, so the photojournalist must move fast and capture people in natural positions to ensure they are not putting on an act for the camera, he noted.
Digital technology and the internet may have boosted the speed at which things happen, but the basic work of the photojournalist remains the same, he insisted.
"Our duty is to be good ... People want you to tell their story, and the public wants you to tell that story - but with talent. If not, it is sordid, it serves no purpose," he said. "You have to do the job well."