How can we be sure of the world we live in? Can we assume that what we perceive is “true”? Can we still rely on our senses? What do our sense perceptions tell us about the world? How does perception function? How reliable and credible is what is visible? These are the kind of questions that arise on entering a room in which Werner Klotz has installed technical appliances of perception. He sets up what seems like a science laboratory full of optical instruments and perception appliances-binoculars, periscopes, stethoscopes, optical lenses, all sorts of reflecting objects and kinetic instruments which, as soon as they are used, give rise to serious irritations: images become superimposed in the observer’s brain and merge into new units; the eyes have difficulty focusing. These are training units aimed at sharpening our subjective sense of vision, apparatus of perceiving one’s own perception, or “perception instruments”, as Werner Klotz himself calls them.

UNIDAD Syndrom (1992) is a two-part perception instrument which allows the observer to look and listen into another space. It consists of a glass mirror box through which specially blown glass tubes lead. The other part of the instrument is a hemispherical mirror. When looking through the periscope one eye sees a distorted mirror image of the world in the hemispherical mirror, as well as the word DAD engraved on the mirror; at the same time one hears warped sounds through the stethoscope. With the other eye one sees oneself on the back wall of the glass mirror box, plus the word UNI engraved in the glass of the box. In order to make a unit out of the two fragments of the word, one has to “look through the periscope attentively, precisely and without distractions…This is difficult, but can be trained using this instrument”. After a while, the spatially separate parts of the word UNI/DAD appear to the observer’s eye as a single unit (unidad). Another perception instrument called the Cheval Syndrom (1992) facilitates another kind of “world view”. Outwardly it is constructed like a pair of binoculars, but the lenses reproduce the distant and the immediate areas equally sharply. This is how horses see, so what does the world look like through the eye of an insect? The Instrument (1992/96) simulates “scientific observation”, although ultimately it refers the observer “to the subjective contingency of his vision”. The eye is constantly in search of the right focus, which again and again casts doubt on the water-filled construction; only the noise level from the street heard through the stethoscope assures the test person that he or she has ‘all his wits about him’. The Fernglaeser (binoculars), however, the anticipated close-up of the distance blinds the viewer; in another, as in the Intellektuellenfalle (1995), one eye glimpses itself, the other an apparently endless “eye room”-a “kaleidoscope-like cabinet of mirrors divided according to the principles of Euclidean geometry, with as many cubic cells as round holes, each with a seeing eye”. The Fernglaeser avail themselves of binocular vision, which is necessary for man’s perception of space: “If the eyes…receive different optical impressions, for example, when in a binocular object one eye is reflected in a concave mirror and the other, by contrast, perceives a section of a landscape, then after a short space of time the two perceptions… become superimposed and form a new unified image which exists solely in the observer’s brain. A temporarily limited, fantastic artificial image emerges…” The kinetic work Anemone (1996) also gives rise to such a phantasmic temporary image without a reference: it consists of a shining hollow silver sphere installed on a reflecting floor panel; the hollow sphere is made up of six segments tapering to a point (“petals”). As one approaches, the Anemone begins to revolve around itself and unfold its “petals” which have mirror surfaces on the inside, thereby reflecting the observer who triggered the movement. Due to the eye’s sluggishness (persistency of vision), the light impression remains for about 1/0 of a second after the impact of the light (the after-image) and for a brief moment causes a quasi three-dimensional image to emerge.

Werner Klotz creates “aggregates by means of which we can experience the certainty of what is only apparent and the deceptiveness of the real”. His perception instruments intervene at a decisive break in the history of perception and make it possible to experience this on-going process which began in the early nineteenth century and brought about a radical modernization and reevaluation of vision and visual experience as well as an “extensive restructuring of the observe” (Crary). In the nineteenth century, a growing awareness of the arbitrary and non-referential nature of images gave rise to a “scandal in the theory of perception”, while in the twentieth century, the age of the “zero-dimensionality” of images, of simulacra, and of Baudrillard’s hyperreeal”, in brief, the era of digitization, i.e.,computerized images, this process is being continued is a highly radical fashion.

The breach between tactility and visuality

According to the American art historian Jonathan Crary, the modernization, reevaluation and increasing abstraction of vision began in the early nineteenth century. The observer had been fundamentally “reorganized…in the nineteenth century before the appearance of photography. What takes place from around 1810 to 1840 is an uprooting of vision from the stable and fixed relations incarnated in the camera obscura… In a sense, what occurs is a new valuation of visual experience: It is given an unprecedented mobility and exchangeability, abstracted from any foundation or referent.” Whereas the sense of touch was an integral component of the classical theories of vision in the seventeenth and eighteenth centuries, in the early nineteenth century the sense of vision and the sense of touch became separated “within a pervasive ‘separation of the senses’ and industrial remapping of the body…” Vision was then no longer seen as analogous with touch, which also meant “loosening of the eye from the network of referentiality incarnated in tactility and its subjective relation to perceived space”. According to Crary, the stereoscope is “one major cultural site on which this breach between tactility and visuality is singularly evident”; it is “a crucial indication of … the subsumption of the tactile within the optical”.

Cray’s thesis may seem all too foreshortened, given that by turning “monoscopic” into “unified” he confirms the success of reference and representation until 1800, and diametrically opposes the whole to the later stereoscopic, non-referential and subjective vision. He would seem to repress all the ambivalence that is also inherent in monoscopic vision. Even the attribution of the term “arbitrary” is unconsciously arbitrary. Yet the transition described by Crary from the paradigm of the camera obscura and its inherent geometrical optics in the seventeenth and eighteenth centuries to the paradigm of the stereoscope and its physiological optics in the nineteenth century (investigation of subjective vision) is still of interest here, for this was accompanied by the development of a series of optical devices which in the late nineteenth century became components of mass culture.

Subjective vision and the separation of the senses: The exposure of the “referential illusion” in the nineteenth century

In his Theory of Color (1810), Goethe describes the wide-spread use of the camera obscura for study purposes. Through a tiny hole in the wall light falls into a dark room, throwing a bright image of the world outside onto a round piece of white paper. Then suddenly Goethe recommends doing the following:
The hole being then closed, let him look towards the darkest part of the room, a circular image will now be seen to float before him. The middle of the circle will appear bright, colorless, or somewhat yellow, but the border will appeared. After a time, this red, increasing towards the center, covers the whole circle, and at last the bright central point. No sooner, however, is the whole circle red than the edge begins to be blue, and the blue gradually encroaches inwards on the red. When the whole is blue the edge becomes dark and colorless. The darker edge again slowly encroaches on the blue till the whole circle appears colorless.”

The optical experience described here by Goethe shatters the classical model of vision. The “colored circles that seem to float, undulate, and undergo a sequence of chromatic transformations have no correlation either within or without the dark room”. The nineteenth century saw a transition to “physiological optics”; step by step, the human body became the active producer of visual experiences, “phenomena that have no external correlate. Vision was newly defined as “the capacity for being affected by sensations that have no necessary link to a referent”. The description of a “fundamentally arbitrary relation between stimulus and sensation” and the exposure of referential illusions-the loss of referentiality-became an “epistemological scandal”. Subjective vision, the physiology of the human subject, was itself made a subject of science, of observation and research, and also became regulated and disciplined.

Everything that the eye sees (but the body can no longer touch) is now raised th the status of optical truth. The Czech Johann Evangelista Purkinje, who worked in Germany, was the first after Goethe to “study afterimages… as part of a comprehensive quantification of the irritability of the eye”. With the help of experimental perception psychology, the laws if vision and the mechanisms of perception (after-image, peripheral distortion, binocular vision, thresholds of attention) were subjected to methodical research for the very first time. In 1824, Dr. Peter Mark Roget discovered the persistency of vision. Since the mid-1820’s, the experimental examination of the after-image (as a result of persistency of vision the light impression remains for about 1/20 of a second after the impact of the light) led to the invention and construction of a series of optical devices and techniques, so called “philosophical playthings”. Soon these devices gave rise to apparatuses for entertaining the masses. The thaumatrope (1825) clearly illustrated the gap between perception and object: When discs printed on both sides (for example, a bird on one side, a cage on the other) are made to revolve quickly; the eye perceives a bird in a cage. The phenakistoscope (eye deceiver) of 1833 is held up in front of a mirror and turned; for a split second the observer sees positions from a sequence of movements (for example, of a horse) through the slits. Because the visual impression remains on the retina for a short time, it would seem to the eye that the figures in the images were actually in motion. Other items developed in the 1830s were the kaleidoscope, the stroboscope and the zootrope (wheel of life), a cylinder rotating on its own axis on which simulated movements became visible.

Although the commercial dissemination of the stereoscope in Europe and North America only began around 1850, its development (above all, by Charles Whearstone and Sir David Brewster) is closely linked with research done on subjective vision in the 1820s and 30s. The stereoscope made use of binocular vision based on man’s perception of space, i.e., the fact that each eye sees a slightly different image from a slightly different perspective.

The effect of the stereoscope was “not simply likeness, but immediate, apparent tangibility “, whereby that tangibility had become a purely visual experience, a simulation, as had the effect of depth or space produced solely by the structuring of optical points of reference. In Crary’s view, the stereoscope stands for a “radical repositioning of the observer’s relation to visual representation”. In particular the first model of the stereoscope , by Wheatstone, “made clear the atopic nature of the perceived stereoscopic image, the disjunction between experience and its cause … It left the hallucinatory and fabricated nature of the experience undisguised … There simply was nothing ‘out there’. The illusion of relief or depth was thus a subjective event and the observer coupled with apparatus was the agent of synthesis or fusion.” Nevertheless, in the course of the nineteenth century these “philosophical playthings” – especially the stereoscope, which warned against the “mere appearance” of images by exposing the function in an altogether enlightening manner-were replaced by other techniques apparently more suited to upholding the “referential illusions” (Barthes). The logic of simulation was perfected in the twentieth century.

After the loss of referentiality: The logic of simulation and the observer’s entry into the image

The era of “zero-dimensional images” is in the process of perfecting the logic of simulation. The image’s loss of referentiality, however, certainly did not mean the much invoked “death of representation”. On the contrary, the basic laws of representation remain effective in simulation.

In the era of simulation, the capacity to evaluate, categorise, and handle information is becoming more and more important. Given that they are oriented around the fundamentals of human perception, or begin with these, Klotz’ perception instruments are metaphorical training instruments for a media competence appropriate to the twenty-first century. And just as Walter Benjamin once claimed, with regard to the nineteenth century phenakistoscope, that “technology subjected the human sensorium to a complex kind of training”, so too Werner Klotz’devices-for example the Gymnasium for the Eyes (1999)-allow us to practise how to deal consciously with the non-referentiality of images of alternative worlds. Because these machines refrain from showing the observer the world, or perception of the world, in the familiar manner, they no longer accept representation as given, but instead show it as being the result of an agreement, the condition of all communication. Knowledge of non-referentiality highlights the necessity of this agreement.

Whereas the three-dimensional space of the nineteenth century stereoscope was still a copy taken from one (or two) fixed positions in space, space in the computer era is made up of points, is a calculated space in which the observer can move around. The observer now to be found in the image-in the Sisyphus Syndrom (1992) he can even see himself from behind when he looks through the periscope-becomes an appearance that appears to itself; here he playfully learns to produce the necessary references between himself and the images, so as to be able to move about with ease ina ll sorts of projected worlds: We are becoming adult. We know that we are dreaming.”