If you watch movies you’ll have seen umpteen deaths, sometimes in a single film. (According to the people who keep a tally of such things, the final Lord of the Rings has cinema’s highest body count, of more than 800 – though presumably that includes orcs.) But what about the dying process itself? What happens to a body that is dying? A taboo-breaking new documentary filmed inside a hospice on the Isle of Wight controversially features a seven-minute scene of the final moments of Alan Hardy, a retired north London bus depot manager.

Island is directed by the artist and film-maker Steven Eastwood. It started life as an installation commissioned by the Fabrica Gallery in Brighton. Eastwood spent 12 months at the Earl Mountbatten Hospice in Newport between 2015 and 2016, working with terminally ill patients, four of whom appear in the film. What’s so dramatic about the footage of Alan’s death is how undramatic it is. I don’t know what I was expecting, a deathbed scene like the movies, perhaps: Alan mustering a few profound last words to make sense of it all, or a glimmer in his eyes as life flashes before him.

Instead, for seven minutes, Alan’s drawn-out breaths become further spread apart until they stop. Medicated to blankness, he goes gentle into the night – thanks to the unfailing dedication of the hospice team who’ve carefully managed his death over two days.

I tell Eastwood I was expecting something more. He nods. Other people have said the same thing. “What’s interesting is there isn’t an image. You can’t see the dying. I think that’s fascinating, because to talk about how the film shows you the moment of death, I don’t know when that moment is. I’ve watched it over and over. I still find myself thinking: is he going to breathe again?” As it happens, when the end came for Alan, Eastwood was asleep – you can hear him snoring gently off camera. “I’d been filming continuously for 38 hours, so the nurses put a little mattress on the floor. I laid down 20 minutes before he died.”

How did he feel when he woke up and realised Alan was gone? “Elated, I really did. I could clearly see that his death had been very cared for, supported and painless. His death had been as a good a death as you could ask for.” The camera stays switched on as the nurses wash Alan’s body and comb his hair; their tenderness and respect are deeply moving.

Eastwood had just started volunteering at his local hospice in east London when he saw the gallery’s call-out for submissions on the subject of end of life. What interested him about filming in a hospice? “I realised that there weren’t a lot of films about end of life. I just thought: how strange that there are very poor descriptions of something as natural as death, that’s happening on every street. In the history of visual art, there’s so many depictions of deathbeds. Isn’t it interesting that it’s fallen out of the space of art?” He mentions two contemporary artists who’ve tackled death through their work, Sophie Calle and Bill Viola, who both filmed their mothers as they lay dying.

But why are there so few films that look death squarely in the face? A quick search on Google for “films about death” throws up a random list that includes Bambi (fine if you’re seven); Flatliners, the hokey 80s thriller about medical students messing about with defibrillators; and The Death of Stalin, Armando Iannucci’s Soviet-era satire (which, yes, opens with Joseph Stalin carking it, but no, doesn’t have much to say about mortality, unless you’re the feared dictator of a totalitarian state). You’ll find the web’s longest list of films about death on the website Urns Online, which promises everything from “light comedy to stark and depressing art films”.

The fact is that serious dramas involving death tend to focus more on dispelling stigma around illnesses – Aids in Philadelphia, Alzheimer’s in Away from Her – than the dying process. You can picture a director pitching a mortality-themed script to financiers: “I’m thinking hospital ward. I’m think nursing home. Let’s show them what really happens when you die. Whaddya think?” Stony silence. So perhaps there will always be a gap between fiction and reality.

But documentaries do push the limits of what can be shown on screen. In 2003, Allan King filmed five terminally ill patients in a hospice in Toronto for his vérité documentary Dying at Grace. During the Aids crisis, a number of films intimately chronicled men dying from the disease (Silverlake Life: The View from Here, Common Threads: Stories from the Quilt). Controversially, the 2006 film The Bridge showed the actual suicides of people leaping to their deaths from the Golden Gate bridge in San Francisco. Director Eric Steel set up a camera to film the bridge 24/7 for a year, then interviewed friends and families of the jumpers. The Bridge divided critics – ghoulish snuff film or poetic meditation on suicide?

Werner Herzog is a director famed for staring death in the eyes and not blinking. Yet even he refused to play the audio of a real-life death in his documentary Grizzly Man, about the naturalist and film-maker Timothy Treadwell, who was killed by the bears he was observing in the wilderness of Alaska. Perhaps the most crass and deplorable example of death on screen came 40 years ago in the cult shock-doc Faces of Death, which claimed to feature authentic footage of real-life deaths, human and animal. It turned out around 40% of scenes were faked – including a man being eaten by an alligator.

Facebook Twitter Pinterest Werner Herzog’s Grizzly Man did not commit its real-life death to film. Photograph: handout/Handout

Why do we have this taboo of showing death on screen, I ask Eastwood. “This what interests me as a maker. We carry with us a lot of folk wisdom or rules about what we think is appropriate. And I think we sometimes don’t check in with ourselves about whether that has any bearing any more.”

In the weeks before shooting Island, he experienced two bereavements himself: “My partner at the time’s mother – the grandmother of my children – and my closest friend died within weeks of each other. I was already in that mental space. So, I was able to say to people I was talking to about the film that I’d just had a bereavement. I wouldn’t have asked for it to be that way …” His voice trails off.

Virtually all the terminally ill patients Eastwood approached on the Isle of Wight were interested in meeting him to talk about the film. “They were quite happy with a camera coming into their life at that time. I think the assumption is that it wouldn’t be wanted.” Alan used to joke that he was Eastwood’s Charlton Heston. “I think he really enjoyed leading-man status, and the attention.” Alan, it turns out, had strong beliefs about life after death. Earlier in the film, he tells the camera that he’s convinced the core of him will live on. He wants to see his wife again in the next life. “I’ve got plans. I’m going to take up ballroom dancing.” Does he think immortality – the chance to live on in some way on film – motivates his subjects, I ask Eastwood. “I don’t know. I didn’t really discuss legacy with them.”

Facebook Twitter Pinterest Leading-man status … Alan Hardy.

It was the nurses that he struggled to get in front of the camera. Five months into shooting, he called an emergency meeting at the hospice. “I showed them a rough cut of the film, and I said: ‘It looks as though nobody is receiving care in this building.’” Why does he think they were so reticent? “I think they’re trained to be selfless.” One of the things that struck him watching the nurses was how much time they spent on the non-medical stuff. “What happens if this person’s estranged father turns up? Their gay partner? All these people are brought together in one room, and the nurses have to manage all of those emotions while delivering medication. Hospices are a space of life. All the drama, all of the emotions, all of the joy. Everybody had a dread of them, but I think they’re some of the most progressive spaces in our society.”

Eastwood believes that hospices should be more visible in the community to remove the stigma around terminal illness and dying – to make death more familiar, less frightening.

He compares our squeamishness around death to how society used to view childbirth: “Fifty years ago there weren’t many photographs or films of births, but now that’s understood as a celebration of our bodies.” People have come up to him after screenings, telling him the film has made them less scared about dying. “There’s lots of research that shows that being better informed about what happens to our bodies when we are dying can alleviate anxiety.”

If Alan’s death feels natural, the tragedy of the film belongs to Jamie Gunnell, a 40-year-old lorry driver and father of two. He was diagnosed with stage-four cancer after going to his doctor with a stomach ache. “It came out of nowhere for him,” says Eastwood. “Jamie went through a lot.” In the film you watch Jamie and a couple of his mates sitting in his room at the hospice watching football with a few cans of Guinness on the go. It’s oddly very moving to see these blokiest of blokes joking about cancer. “Fucking hell,” says one of them watching a nurse drain the contents of Jamie’s stomach into a bag. “Looks like chicken stock.”

Island review – unblinking vigil at death's door Read more

Eastwood says that Jamie and his mates were determined to “continue their relationship on normal terms”. And business as usual meant booze and banter. “Guinness cans and football, smoking a joint out the back, that’s how he wanted to die.” Still, the film’s most haunting images are of Jamie, his face stricken by fear and confusion – totally alone, as if he is already seeing the world from the outside. “He went through period of anger and desperation, but then would bounce back, and his humour was always there. That was his way of normalising it.”

Eastwood says that nurses talk about something happening when a patient is very close to death – the temperature changing in the room. Has making the film changed how he feels about death and his own mortality? He shrugs. “I take a pretty stoical view on it. I don’t feel any great fear about it. I’m very aware that I’m an animal, a biological thing. Possibly, it has made me feel reassured.”

“The chances are I’ll probably die in a similar way [to Alan], if I’m lucky enough to get to late life. Most of us will die of cancer or heart disease. Or dementia. And that will almost certainly involve some kind of end-of-life palliative care support. I don’t think you can overstate how extraordinary these people are. They’re just brilliant. I loved going back to that hospice, because I loved being around those people.”

• Island is released in the UK on 14 September.