A thought on The Revenant, note this post contains minor spoilers.
In the introduction to the book Digital Light, Sean Cubitt and his collaborators relay the story of the first ever filter created for Photoshop: the lens flare. As they tell the story, the lens flare was first used by the George Lucas-owned special effects house Industrial Light and Magic to add realism to scenes created entirely by computer, thereby increasing the apparent realism of the scene. In a similar vein, graphic designers found adding artificial highlights to images could give an impression of volume to two-dimensional images. Its heavy use in the 1990s, the authors suggest, made the lens flare something of a “hallmark of digital images”. 
I was reminded of this story last night while watching a film very different from Lucas’s Star Wars: Alejandro González Iñárritu’s The Revenant, the story of frontiersman Hugh Glass’s  journey through the harsh winter in search of revenge against John Fitzgerald,  the man who murdered Glass’s son and left him for dead following a brutal bear attack. The film is a bleak and brutal one, but there are also instances of incredible beauty. I had previously read that the film was shot entirely on high-definition digital cameras using only natural light, the latter an effort to heighten its ‘realism’. According to the film’s Director of Photography Emmanuel Lubezki, the decision to use digital instead of film was because film did not have the sensitivity needed to capture scenes shot at dawn and dusk.
Interestingly, he then goes on to state:
“It [digital] allowed us to (work) without any noise of grain between the audience and the actor […] It’s a little like watching everything through a window; it’s clean, and there’s no texture between you and the character.” 
Granted, the digital cameras do eliminate the noise commonly associated with film grain, but I did not get the sense of ‘watching everything through a window’ that Lubezki describes, because the camera seemed to me very present throughout the movie; to the extent that I found myself wondering if making the camera’s presence known was, like the decision to shoot only in natural light, a deliberate attempt to heighten the ‘realism’ of the film.
Lens flares from the sun occur frequently throughout The Revenant, but they are far from the most forceful way in which the camera is ‘made present’. In one scene, Glass, fleeing from a tribe of Native Americans, is swept away by strong river currents. The camera follows him down river, plunging in and out of the water, causing a number of water droplets to adhere to the lens. In another scene towards the end of the film, Glass tracks down and confronts Fitzgerald, leading to a brutal knife fight in the snow, during which specks of (presumably fake) blood splatter on to the camera’s lens. In multiple close-up shots of Glass’s face, the lens appears to fog from the actor’s breath.
In these scenes, the distortions to the image, caused by fluids or breath on the camera lens, dirt on the window if you like, remind us of the camera as a physical object engaged in the action: it is made present. It is true that a camera always intervenes in the image making process, but its presence is rarely so apparent as when it picks up on physical matter thrown up by its subjects. We are compelled to acknowledge the presence of the camera and the physical nature of the action it depicts: the chaos of a fast-moving river, the extreme cold of the landscape; the blood spilt in a brutal knife fight. For me personally, this last caused me to flinch – despite the fact I knew what I was watching was all carefully staged.
The Revenant uses the presence of the camera to heighten the reality of its filmmaking, to underscore that what we are seeing on screen appeared before the lens of a camera, but it also underscores the need to distinguish between ‘realism’ and ‘truth’. What we see might true inasmuch as the majority of the film’s special effects are physical as opposed to computer-generated ones, what we see did appear before the lens of the camera, but they are not true in the sense that they record ‘real’ events. The film may be loosely inspired by historical events, but it is ultimately a work of fiction and it is unlikely that any viewer could mistake it for anything else. Everything on screen was carefully staged for the camera, and while the ‘dirt on the window’ may not be deliberate, it seems, in its presence, to suggest, in a similar manner to the shaky and pixelated footage recorded on a camera phone by someone bearing witness to an event, a camera that just so happened to be there to capture the action.
1. Cubit, S., Palmer, D., and Tkacz, N., “Introduction”, in Digital Light, eds. Cubitt, S., Palmer, D., and Tkacz, N. (Ann Arbor, MI: Open Humanities Press, 2015).
2. The part of Hugh Glass is played by Leonardo DiCaprio.
3. The part of John Fitzgerald is played by Tom Hardy.
4. Quoted in: Jenelle Riley, ‘‘Revenant’ Cinematographer Emmanuel Lubezki Used Only Natural Light,’ Variety [online]. 15 December 2015. Available at: http://variety.com/2015/artisans/production/the-revenant-cinematography-emmanuel-lubezki-1201661435/ (accessed 17 February 2016).