FOR all adults with beloved children in their lives, seeing Alan Kurdi’s toddler body prostrate at the water’s edge is like a nightmare made real. It’s the kind of mental image that shoots you bolt upright in the middle of the night, panting with relief that you’re under a familiar quilt, and that your darlings are safely located. But there’s no relief with this picture.

And thus – even in a digital age where we presume almost any image can be manufactured – here is the power of photography. Or to be exact, press photography. Dispatched by her Turkish news agency to observe Europe-bound migrants in the area, the 29-year-old photographer Nilufer Demir came upon the bodies of Alan and his five-year-old brother Ghalib on Ali Hoca beach, around 6am this Wednesday.

“As I found them dead, all I could do was take these pictures, to be their voice,” Demir said on Thursday.

So around this image – and its partner, where the note-taking soldier lifts Alan’s body in his arms – we have an undeniable, verifiable news context. This comes at the peak of a pile of images generated by journalists who (it seems to me) are taking every chance to bear witness, reporting a surge of human suffering that no government official can remotely deny or mitigate. And out of their collective efforts, perhaps this photo is the tipping point.

There is something very particular about photography’s effect on us. In a tweet the other day, I paired Alan’s picture with that of Phan Th? Kim Phúc, the naked girl running from the US military’s napalm attack on Tr?ng Bàng village in Vietnam, taken by Nick Ut in 1972. Historians have cited it as playing a crucial role in turning American public opinion against the war.

But like Alan’s picture, this is a single slice from a teeming reality. Does it tell us that the napalm bombing was, in fact, accidental? Does it indicate that Phan Phúc survived to adulthood, and now lives elegantly in Canada? Yet this is the very point of news photography: it emotionally engages us to ask questions, endless questions, about the reality it has seized and frozen before us.

We can readily document the world with moving images these days – there’s footage everywhere, received or produced, only a smartphone away. But a still photo, paradoxically, can make us more active as viewers – and more empathetic in our gaze.

There they are, fixed in the frame – two arms, two legs, two ears, two eyes (or that number to begin with, at least). Gaze on: the longer you look – and a photo allows you to linger, it doesn’t sweep you on to the next edit – the more you wonder. What might it feel like to be a fellow human, under those conditions?

The French critic Roland Barthes gave all photographs two functions. The first he called, using Latin, “studium” – the historical, social and political reality that any photograph of our human world contains. The second he called “punctum” – that detail of a photo that pierces us to the heart, for joy or for grief.

Barthes made this second function a private, subjective affair. But isn’t there a universal “punctum” that can be induced in us, as vulnerable human beings? Particularly when the Terror of War (as Nick Ut’s original photo was titled) bears upon children?

And not just war. Pablo Bartholemew’s 1984 picture of the child being buried by her father after the Bhopal gas disaster – her unearthly pallor, her blanked-out eyes emerging from the scrabbled earth – is the image that cautions every corporation to tighten up its safety rules.

Yet even in acknowledging the humanistic power of news photography, a cautionary note pops into the head: Don’t overuse, or (worse) abuse it.

During a business trip a few years ago, I visited the War Photo Museum in Dubrovnik. The exhibition on at the time (by the Agence VU photographer Cédric Gerbehaye) took the peoples of Sudan as their subject. Gerberhaye photographed the run-up to the July 2013 referendum which formally separated Sudan into North and South, after a civil war that had left an estimated two million dead.

I doubt I have ever seen more formally beautiful or striking colour photographs in my life. The desolation of the landscape was a setting for the extraordinary poise, and the sartorial flair, of the subjects – whether they be flag-wavers or amputees, water carriers or playing children.

But did I really trust what I saw? Were those human poses in the picture happened upon, or were they carefully arranged? Was that startling colour palette actually there, or was it a result of technological enhancement?

The questions of artifice and digitality sneak in everywhere – and this year, they have penetrated to the heart of the snappers’ profession. My friend Stephen McLaren, the Scots-born street-photography guru, has alerted me to the crisis that beset this year’s World Press Photo Awards.

An Italian photographer was stripped of his first prize, for a sequence of photos about the seamy street life of Charleroi, Belgium. It was discovered that one of the pictures – a couple having sex in their car – was enabled by a flash inside the vehicle, remotely triggered by the photographer ... who was himself the cousin of one of the doggers.

This was a set-up for “portraiture”, said the judges, and therefore not a news picture. But they also revealed that 20 per cent of the photos had been disqualified in previous rounds, mostly because they had used digital techniques to hide objects that were present in the original file.

The World Press Photo awards recently published a study titled The Integrity of the Image, where they attempted to distinguish “minor” from “excessive” digital changes.

“Excessive” means “additions or subtractions that deliberately intend to mislead the viewer”. And “minor” means being allowed to use “limited cropping, toning, dodging and burning, colour adjustment, conversion to grayscale”. Which still seems, to this inexpert observer, like a lot of visual leeway.

Some cynics have noted that this is more a crisis of those who want to win photography awards, than of photography itself – the competitive pressures of the business pushing some ambitious snappers beyond the profession’s ethical standards. And no doubt old habitués of the chemical darkroom will come forth to reveal their secrets.

But there is clearly a looming crisis for news photography here – as in, it must be said, all other areas of image culture. Think of how convincing simulated human characters have become, over the last decade of movies and computer games. How close are we to simply not knowing who is digital or who is flesh in any image, whether moving or static?

It’s all very slippery. My other picture-tweet this week was of the 2014 World Press Award overall winner, John Stanmeyer’s Signals, in which African migrants at Djibouti City hold their phones to the night sky, trying to catch a cheap signal from nearby Somalia.

Exposure tweaked? Colour adjusted? I suspect yes – but what a slice of yearning, aspiring humanity is given form and expression here. And again, true to the news photo’s nature, its “punctum” triggers a cascade of questions. What messages, from what individuals? What is their life story? What happened to them? How am I implied? What can I do?

The photographer’s finger clicks – wherever she or he is, and on whatever device – and tries to be “the voice” of who is before them. And not in spite of, but because of all the grief it causes us, we must grant integrity to the act of photographing a dead toddler’s body in the sea. Some nightmares are real – and someone has to show them to us.

Pat Kane is a musician and writer (