Before the 19th Century, the vision is described as that there was a direct correspondence between the observer and the object, much like camera-obscura produces the true representation of the external world. People like Richard Rorty or Descarte's ideas on observation are based on this camera-obscura model that secured the position of the self at the center , and this idea clearly shows the distinction between the inner and the outer world. However, in 19th Century, physiological study done by Goethe or Muller revealed that the perception of the external world goes through our body and the stimulus from outside are processed on sensory nerves. For example, the analysis of the afterimages which was previously thought as illusion was studied by major scientists at that time. Johannes Muller, the major theorist of vision in the first half of the nineteenth century, came up with the "doctrine of the specific nerve energies" in which the specialization and division of human sensory system was discussed. This introduction of body between observer and object collapsed the line camera-obscura system was creating between inner and outer world. The secured position of an observer is taken away. Our perception depends on how our bodies process the stimulus from the external world anymore. As a result, the vision in 19th century became autonomous and subjective.
Uta Barth's photographic series Ground consists of about fifty images varying in size and shapes of rectangular, of landscape and interiors, which