The Getty's Engaged Observers will always be eye-opening

"An ample reservoir of stoicism is needed to get through the great newspaper of record each morning, given the likelihood of seeing photographs that could make you cry," Susan Sontag wrote in her 2003 essay Regarding the Pain of Others. If this sentiment now seems dated, it's not because the news is any less upsetting, but because Sontag blithely assumed that such shocking and disquieting images would continue to arrive with the morning paper for ever. But photojournalism rose with the international newspaper, and may fall with it. With more print periodicals disappearing every year, the kind of everyday confrontation with contemporary social problems that Sontag took for granted is becoming rarer. Increasingly, readers encounter such pictures only over the internet, where they have seemingly unlimited choice and access, but also an unprecedented power to filter out disturbing images of war, poverty, revolution, or anything else they might not want to think about or see. In a time of such uncertainty for the medium, it's useful to have an exhibition like the J Paul Getty Museum's Engaged Observers: Documentary Photography Since the Sixties, which makes the case that serious, socially conscious photojournalism has flourished independently of the print media for decades. All the pictures on display, though often commissioned by the likes of Life or the Observer, were intended for publication in book form, rather than appearing piecemeal in newspapers or magazines. The result is "not a photojournalism destined for the morning's headlines", curator Brett Abbott writes, but a "self-assigned form of reporting" that allows for greater depth and nuance than most conventional news outlets can provide. After a potted history of early documentary photography from Jacob Riis to Robert Frank, the show launches into the 60s, with seminal works on the civil rights movement by Leonard Freed and the Vietnam war by Philip Jones Griffiths. Salgado's Migrations: Humanity in Transition series moves from desolate shots of Sudanese refugee camps to astonishing images of crowds in the Churchgate railway station in Mumbai, taken at a very slow shutter speed, so that the white-clad bodies of the travellers blur together into undulating lines. Smaller in scale but no less dramatic in effect, Lauren Greenfield's heartbreaking portraits of teenage girls in southern California report from a world where anorexia and rhinoplasty are as much coming-of-age rituals as Sweet Sixteen parties. Most timely and affecting of all is James Nachtwey's The Sacrifice, a nine-metre-wide collage of 60 black-and-white snapshots taken in field hospitals and trauma centres in Iraq. The accumulation of human detail in Nachtwey's work is overwhelming. Shooting from low angles, he gets close enough to read the names on the medics' dog tags, the text in a chaplain's prayer book, or the numbers scrawled on patients' bodies for triage purposes. Any of these images, encountered at random in a newspaper or online, would stop you in your tracks. Taken together, they have a monumental, almost religious power. The case for photojournalism's independence from print is arguable, though passionately made by this show. True, book publication allows photographers more control over the presentation of their work, and lets them resist the pull of the media. These now-iconic shots introduce and frame newer work.But the independent approach also brings disadvantages: the relatively small circulation of the images, the absence of editorial input and, in some cases, a wider factual context. Still, whether one feels that the tradition of engaged observation celebrated here is thriving or threatened, the Getty's exhibition makes a powerful argument for its importance. Beyond their own considerable merits, both as reportage and as art, these pictures tell an important story about the future of news.