At first glance, Danfung Dennis' Hell and Back Again gives the impression of a highly cinematic fiction film. Terrence Malick's latest war epic, perhaps? The filmmaker's access is so intimate, the sound design so engaging, and the imagery so arresting, it's unfathomable that the film could be shot, and the sound recorded, by one man.

But it was. And its success is the result of a confluence of factors--right place, right time, right characters--but perhaps most remarkably, the filmmaker's unrelenting tenacity learned from years working as a war photographer, and the fairly recent development of the Canon 5D Mark II--the first (and perhaps still the best) DSLR camera that can record 1080p HD video.

The film takes us deep inside the war in Afghanistan, where we join a US Marine Corps unit on a mission to take down a Taliban stronghold in the South. Sergeant Nathan Harris leads the charge but is critically injured in battle, and returns home to his devoted wife in North Carolina to rehabilitate. The film contrasts his brutal, albeit exhilarating, experiences on the frontlines in Afghanistan with the mundanities of life back home--shifting back and forth between the grand vistas of the war-ravaged country, to the claustrophobic view from the back seat of Harris' car as his wife drives him to doctors' appointments and fast-food drive-thrus. We witness Harris' struggle with depression and his growing dependence on painkillers with a painful intimacy rarely captured in documentary film.

The 5D Mark II was the ideal camera for both settings, says the filmmaker, mainly because it's a small camera capable of superlative, cinematic-image quality. "I think that was one of my aims," Dennis maintains. "To borrow from the language of cinematic film and bring it to documentary...I wanted people to forget that they're watching a documentary, and when they realize that it's real, it hits them that much harder, and conveys that much more emotion."

Dennis spent eight months customizing his rig for shooting in Afghanistan, which he designed to fit into a backpack. "Other film productions have big crews and cases and cases of equipment. They're very slow-moving and encumbered and the shots reflect that:  They have to set up a tripod, and sort of manufacture their shots. When you work as a photographer, it's much more fluid; you have to stay light and be able to be dynamic to whatever's happening around you."

But as anyone who's used the 5D on a documentary knows, the camera has some serious issues that can impede shooting in dynamic, hand-held situations. "I think when they first designed the camera they had no idea that people would be using it to shoot films," he says. "They thought that they'd shoot Web clips and then take pictures, mostly... I knew there were weaknesses. The audio was a huge problem and the stabilization was a huge problem, so I spent a lot of time testing and re-testing and building some components to get it to do what I needed in these really difficult situations.

"I modified a Glidecam 2000 to accommodate the 5D and my sound equipment [which included a Sennheiser 66 shotgun mic and Sennheiser G2 wireless system running into a Beachtek DXA-2s duel XLR adaptor]," Dennis continues. "Because I was wearing body armour--quite a lot of other weight--I didn't want to be wearing the traditional kind of Steadicam vest. So I got my arms strong enough to hold the entire rig, which is 10 or 15 pounds, and be able to hold it for a couple of minutes for tracking shots. Then I would rest it onto my body armour with an attachment when I wasn't shooting, just to give my arm a break. I spent a lot of time practicing to be able to pull off these shots, to be able to get the kind of fluid motion and move with whomever I was moving with."

When he returned to North Carolina with Harris, Dennis went back to the drawing table and redesigned his rig to suit shooting in closer quarters and in more emotionally sensitive situations where a larger camera setup would prove too intrusive. This time, he used the smaller Zacuto Stryker kit to hold his camera and sound equipment and had a custom follow-focus unit built from a skateboard wheel.

But some issues couldn't be overcome by the rig, no matter how cleverly he modified it.

For one thing, the camera needed to shut off every 15 minutes or so to avoid overheating, especially in the 130-degree heat of Afghanistan. "There really wasn't any way around that," Dennis explains. "I only had one camera body, so I would just limit what I would shoot and only at the most important times would I let the camera roll. It was frustrating--some of the most interesting times I wanted to be filming more, the camera would shut itself off and there was nothing I could do except to let it cool. I also didn't know when I would have another chance to charge my batteries and I had a limited number of hard drives, so I had to carefully calculate how much I should be shooting to gauge the importance of everything that was happening around me and whether it was worth it to even turn the camera on or off."

Dust was also a major problem, Dennis says, and it nearly prevented him from getting those incredible shots from the opening of the film. "Just before the operation started, when all those helicopters were lifting off, there was this incredible amount of dust being stirred up," he recounts. "It got into the camera, and the shutter button got stuck in the down position. I only had about two minutes before the helicopter I was supposed to be on was leaving, and I wasn't able to start recording.

"All these esoteric questions flooded into my mind like, 'What am I doing here if I can't document this? Should I even get on when I don't have my tools? What's the purpose of being here?' And I just took my fingernail and scratched the dust out of the shutter button to pop it back up. I was able to begin recording, and I stepped onto the helicopter and began the operation. So, cleaning it every single day, getting as much dust out as possible was critical."

Keeping things in focus was yet another challenge, particularly because Dennis wanted to shoot at a very shallow depth of field to achieve a cinematic look. "I wanted to be able to ... isolate the subject and direct the viewer to certain points in the frame," he explains. "So I shot almost everything at f2.8 in Afghanistan, and then back in North Carolina even shallower depth of field, so f1.4, f1.2. At that depth of field, you're focused down to a couple of inches, so if anyone moved they'd go out of focus. So I had to re-rack or move with them, and with no auto focus, once you start recording my mind was constantly thinking about focus just my subject and keeping things sharp."

To do this, Dennis says the technicalities of the job have to become second nature. "Your fingers need to work with your mind in a way that doesn't require explicit thinking. It just automatically changes the exposure or the focus. Your tool has to become an extension of you."

But aside from all the specific technical challenges that he overcame, the question of motivation still remains. Where does the drive to go to such great lengths and at such great personal risk to achieve the aesthetic of this film? Turns out the answer lies in his background as a photographer: "It was the past work of other war photographers--mostly from Vietnam, Bosnia and Rwanda," he says. "I wanted to follow in that tradition of trying to contribute images that could burn into the collective consciousness and try to inform others of those realities and try and show what mistakes that society had made so that we don't repeat them.

"And it's very important to always be looking towards new technology to try to shake people from their indifference. It's easy to think of these wars as distant and complex and far away and as an abstraction, that they don't really affect our daily lives. So we do need stories to try to bring this war close to home."

Hell and Back Again is current screening at Film Forum in New York, through Docurama Films; the film opens in Los Angeles on October 14 at the Laemmle Monica, with additional opening dates scheduled through November.

Sarah Keenlyside is a Toronto-based producer and writer.