OBSERVATIONS FROM A FIXED POSITION 
James Langdon 
1 
Georges Perec Images is a book compiling photographs of the celebrated French author. An odd prospect perhaps, but not if you are familiar with Perec’s distinctly expressive face.The photographs chart his transform- ation from the young, soberly dressed man seated doubtfully at the typewriter on page 67, to the mature artist with wild hair and typically mischievous grin on page 163. 
On page 134 are a pair of interesting images. A view of le Café de la Mairie on Place Saint Sulpice in Paris, not dated but likely taken around 1974. It shows the café’s striped awning, the rows of chairs outside facing the street, and the immediate surroundings — trees, benches, a parked car. Beneath this is a portrait of Perec at a window seat in the same café, seen through the glass from outside. He poses con- spicuously as an artist-at-work. On his table are writing paper, cigarettes and a cup of coffee. He looks purposefully out of the window, smiling with a certain satisfaction. 
In the process of writing his short book Tentative d’épuisement d’un lieu parisien (translated as An Attempt at Exhausting a Place in Paris), Perec regularly visited Place Saint Sulpice to observe its routines of every- day life. The text documents his findings prosaically, listing phenomena and speculatively classifying them. The fixed elements: architecture, street furniture and signage, even the ground — packed gravel and sand — and the fleeting: the trajectories of traffic, the gestures of people in motion — carrying a bag or holding a child’s hand.That no particular drama occurs is precisely the point. 
What explains the expression on Perec’s face, seated at the window of Le café de la Mairie? Perhaps it is the realisation that his presence is subtly subversive. His fixed position situates him decisively outside the incidental flow of life, which — it follows — reveals itself only to him, eluding the distracted attention of those who appear in the text — preoccupied by getting to work, shopping, running errands. 

2 
Repeat photography is a documentary practice used in surveying, and in natural sciences such as geology, meteorology and physical geography. A repeat photograph recreates as exactly as possible the composition of an original photograph. 
Second View:The Rephotographic Survey Project is an exemplary publication in the genre. From 1977 to 1979 a group of artists led by Mark Klett, Ellen Manchester, and JoAnn Verburg, repeated a series of 122 photographs made in the late nineteenth century for the United States Geological Survey.The purpose of these original photographs was to record the characteristics of the landscapes of the western United States.The repeat photographs visualise the forces transforming these landscapes over time. 
At first inspection the images reveal predictable narratives. Many pairs chart the domestication of wilderness — the imposition of highways and other manifestations of urbanism on previously remote parts of the country.A barren desert landscape in Green River,Wyoming photographed in 1872 is startlingly transformed in a repeat photograph from 1979. Trees, houses, vehicles, and telephone lines have appeared to obscure the view. At the upper edge of the image a sheer butte of rock that dominated the original photograph is relegated to a background detail. 
Other pairs diverge according to contrary forces.The Nevada landscape, besieged by mining in the nineteenth century, is 100 years later returned to bleakest desert, stripped of its mineral wealth. The mills, heavy machinery and labourer’s accommodations all disappeared. 
The most extraordinary pairs are almost impossible to differentiate. Two photographs of Vermillion Creek Canyon in Colorado, taken 107 years apart, record a landscape uncannily preserved. The camera is positioned at the base of the canyon looking toward the open sky, steep walls of sandstone framing the composition on both sides.The surfaces of rock are highly contrasted, sunlight casting a stark band of shadow across the foreground of the pictures. A sense of romance pervades the details — incidental formations of rock unmoved by the passage of a century.This landscape articulates itself on another timescale.The traces of great expanses of geological time that define it barely register a human lifetime. 
Several appendices establish the technical difficulty in achieving such fidelity to the original photographs. Each photographic image also suggests a counter-image, a reflection of its own making. 
The position, orientation, and specification of a camera and lens can be deduced by studying the image that they produce. More than this, a photographic image identifies itself with a singular point in time. Daily and annual arcs of the sun, seasonal cycles of growth and decay, all leave specific signatures. To repeat the original Vermillion Creek Canyon photograph innumerable factors required calculation: the time of year, the time of day, the position and format of the camera and lens, and on to ever smaller considerations. Even after such extensive preparation, the fidelity of the repeat photograph was dependent on weather conditions closely resembling those in the original. 
3 
The Heidelberg Speedmaster is an archetypal colour offset printing press. In its basic configuration the machine is comprised of four upright modules. Beneath these is a flat bed, along which the paper passes. Each module contains a system of cylindrical rollers — one supports the printing plate, the others ink the plate and bring it into contact with the paper.The rotation of the cylinders is a complex feat of mechanical timing — correct registration of each ink depends on a succession of coordinated meetings between plate and paper.Three modules normally contain the inks used in conventional colour printing: cyan, magenta, yellow (the ‘subtractive primaries’). The fourth contains black, added to achieve a greater depth of colour than is possible by combining the other three inks. A sheet of paper passes through the Speedmaster in a fraction of a second. In the process it is printed four times, the semi-transparent inks layered to create a gamut of colour. 
The modular design of the offset printing press ultimately derives from an historic discovery concerning the perception of colour in the human brain.The process that determines exactly which parts of an image should be rendered in which ink — by which module — is called colour separation.The theory that informs practical colour separation was first published in an 1855 text by Scottish physicist James Clerk Maxwell. Maxwell’s proposition was that a believable illusion of naturalistic colour could be produced as a composite by overlaying three photographs, each having been exposed using a different colour of filtered light. These filter colours were the three ‘additive primaries’ — red, green, blue. The resulting negatives would be processed into positive prints on glass, which could then be projected. In a lecture at the Royal 
Institution in London in 1861, Maxwell — assisted by photographer Thomas Sutton — successfully demonstrated his theory. Three crude colour separations were projected simultaneously through coloured light filters onto a single screen, to create a convincing composite. 
The image that appeared on the screen has become an icon for Maxwell’s work. It is a tightly framed view of a tartan ribbon, tied in a rosette.The ribbon is reproduced in a narrow range of oily blues and purples — the result of inconsistencies in the light sensitivity of the materials available to Sutton. Whether because of focal differences, or misalignment of the separations in the extant copy, the ribbon has blurred edges that seem to subtly vibrate. The contrast is excessive, meaning areas of saturated colour in the ribbon merge with the black background, as if it were partially submerged in murky liquid.The image has the unstable, alchemic aesthetic particular to early photography. 
The ribbon seen by the audience at the Royal Institution was technically three photographs.These colour separations were not de- rived from a single exposure — a process now routinely automated by computer software — but captured manually. Between the making of each of the three photographs Sutton would have had to remove the light filter from the camera and replace it with the next. Each exposure was presumably made in rapid succession, as quickly as the filters could be swapped, to mitigate the risk of difference — in the light, the position of the subject or the camera — occurring in the moments between. The process was crude, but it produces a succinct metaphor for the implications of Maxwell’s discovery — the brain’s synthesis of just three discrete channels of colour into an entire gamut. 
4 
On 12 November 2014, a robotic probe named Philae landed on comet 67P/Churyumov-Gerasimenko, a massive island of rock four kilometres wide and approximately 500 million kilometres from earth. Philae’s journey, aboard the European Space Agency’s Rosetta spacecraft had taken over a decade. Its purpose was to intimately document the surface of 67P/C-G, while Rosetta remained in the comet’s orbit above. It was equipped with an array of instruments, including a camera and imaging system, the ‘Comet Infrared and Visible Analyser’, comprised of — among other elements — six cameras mounted at intervals of 60 degrees around the probe’s hexagonal body, enabling a full panoramic view of its environment. 
The landing did not proceed according to plan.The probe successfully detached from Rosetta, destined for Agilkia, its appointed landing site on the rocky surface of 67P/C-G. Due to the low force of gravity on the comet multiple anchoring devices were required — har- poons, ice screws and a cold-gas thruster. Philae’s harpoons failed to deploy during its initial landing, causing it twice to bounce back into the comet’s atmosphere, eventually coming to rest at an unplanned location, which the European Space Agency’s mission controllers believed to be somewhere in the region now named Abydos, one kilometre from Agilkia. 
The precise location of Philae was unknown.The following day, Rosetta relayed its first contact with Philae to earth. Six photographs from the Comet Infrared and Visible Analyser showed the probe’s immediate surroundings. Enhanced copies of these images were later published on the European Space Agency website. Cameras four, five and six recorded close-up details of the comet’s topography — dense formations of brittle rock — suggesting that Philae had probably come to rest leaning into a cliff face or large rock feature. 
The images from cameras five and six are in heavy shadow, their contrast clearly altered to reveal detail. Parts of the probe’s body are visible in the other three images. Cameras one and three photographed its feet — their intricate, technical aesthetics fitting for a space exploration robot — one grounded on the comet surface, the other suspended in space, giving some clue as to Philae’s orientation. 
The image from camera two is the most poignant of theset. Taken from atop the fallen probe, it looks out aimlessly into space. The blackness is interrupted only by a white linear shape protruding into the bottom edge of the image — one of Philae’s communication antennas. The beauty of the image is its futility. It would probably never have existed — or at least never have been published — were it not for the complications of Philae’s landing. Its lonely perspective offers little scientific insight into the conditions on 67P/C-G. 
The meaning of all six Comet Infrared and Visible Analyser images was shifted by the contingent purpose that they acquired following Philae’s landing. In combination with photographs and other data gathered from orbit by Rosetta, analysis of the images was redir- ected toward definitively locating the lost probe. In this distant drama, Philae’s role became unexpectedly ironic. Designed to explore and record an environment previously unknown to mankind — it was the first spacecraft in history to land on a comet — the function of the probe’s array of documentary technologies became simply to identify itself in the reaches of outer space.