Camera Obscura

Over the centuries, artists have consistently turned to science and technology to enhance their practice and view the world through a new lens. With a 'camera obscura' (Latin for dark room or dark chamber), for example, you can accurately capture your surroundings by projecting the outside world onto a darkened area inside. What's more, no power source is required. So it's not 'magic'; it's genuinely practical science.

The first documented account of a camera obscura comes from a Chinese philosopher named Mozi (or Mo-tzu) in 400 BC, although they date back to as early as 400 BC and perhaps even predate recorded history. He observed that light from an illuminated object passing through a pinhole into a dark room produced an inverted image of the original object. In the 4th century BC, the Greek philosopher Aristotle discovered that a partial eclipse could be observed by looking at the ground beneath a tree. The crescent-shaped partially obscured sun was projected onto the ground through the holes in a sieve and the spaces between the leaves, enabling him to observe it safely. Various other scientists experimented with light passing through a small aperture, but it wasn't until the 11th century that a viewing screen was used to observe the inverted image. Alhazen (also known as Ibn al-Haytham, best known as the "father of modern optics" and a pioneer of the scientific method - the Iraqi polymath) is credited with inventing both the camera obscura and the pinhole camera, which rely on the same principle. He conducted experiments with candles and explained how the image is created by rays of light travelling in straight lines.

Leonardo da Vinci defined the camera obscura very clearly: ‘By allowing the images of illuminated objects to enter through a small hole into a very dark chamber, you will capture these images on a white sheet of paper placed within that chamber close enough to the hole, and you will see all the aforementioned objects on that sheet, in their true shapes and colours; but they will be smaller and inverted…’. A process whose original purpose may well have been magical, and which is thought to date back to the Neolithic period. In antiquity, Aristotle described in detail the use of this ‘stenope’ (‘a small hole’ in Greek), which was useful for astronomy and for understanding how the eye works.

Da Vinci published the first clear written description and comprehensive diagrams of the camera obscura in his 1502 Codex Atlanticus. He drew roughly 270 sketches of the device in his notebooks, using the "dark room" concept to study optics, light behavior, and how the human eye functions.

The term 'camera obscura' was first used by the German astronomer and mathematician Johannes Kepler (1571–1630), who used a darkened tent. The year before, Kepler paused his other work to focus on optical theory. The resulting manuscript was presented to the emperor on 1 January 1604 and published as Astronomiae Pars Optica (The Optical Part of Astronomy). In it, Kepler describes the inverse-square law governing the intensity of light, reflection by flat and curved mirrors, and the principles of pinhole cameras. He also discusses the astronomical implications of optics.  He also extended his study of optics to the human eye and is widely regarded by neuroscientists as the first person to recognise that images are inverted and reversed by the lens of the eye and projected onto the retina.

Kepler wrote, "How that representation or painting is linked with the visual spirits, which have their seat in the retina and the nerve... I will leave it to the physicists to discuss.'

However, it wasn’t until the early 1600s CE that lenses of sufficient quality could be produced to create more versatile cameras with larger apertures. This allowed more light in, producing brighter, higher-quality images. Artists and draughtsmen would once have used a camera obscura like this to create precise, detailed sketches of scenes, such as landscapes or architectural structures, and it was especially valuable for capturing perspective, accurately depicting the height, width, depth and relative placement of objects in the 3D world on a 2D surface.

The camera obscura reached its peak in 1826 when Joseph Nicéphore Niépce, a scientifically-minded gentleman living on his country estate near Chalon-sur-Saône, France developed a technique called heliography or 'sun writing'. This process uses light-sensitive substances on a metal plate, and when the projection from the camera obscura strikes the plate, the image is indelibly recorded on it. This process took an astonishing eight hours, yet once completed, Niépce had created the world’s first ever photograph. It was titled Point de vue du Gras. 

In 1829, Niépce entered into a formal partnership with Louis-Jacques-Mandé Daguerre (1787–1851), the proprietor of the famous Diorama in Paris. Following Niépce's death, Daguerre continued to make vital improvements and introduced his "Daguerreotype" process in 1839. Following this announcement, early supporters brought forth the Niépce Heliograph as evidence of his role in the invention of photography.

The Niépce Heliograph changed ownership several times in Britain during the nineteenth and twentieth centuries, before being purchased by the Harry Ransom Center in 1963 as part of the Gernsheim Collection. The World's First Photograph, housed in its original presentational frame and sealed within an atmosphere of inert gas in an airtight steel and Plexiglas storage frame, must be viewed under controlled lighting in order for its image to be visible. In general, this procedure requires viewing the plane of the pewter plate at an angle of approximately 30° to the perpendicular and in exact opposition to a point source of light, preferably within a darkened environment free of other incidental light sources.

The view captured from a rear upper window of the Niépce family residence in Burgundy depicts (from left to right): the upper loft (commonly known as the "pigeon-house") of the family home; a pear tree with a slice of sky visible through the branches; the sloped roof of the barn, featuring the long roof; short chimney of the bake house behind it; and, to the right, another section of the family residence. The details in the original photograph are quite faint, not due to fading—the heliographic method is relatively enduring—but instead due to Niépce's underexposure of the original plate.