40|REPORTAJE James Turrell. Ronin. 1968. © James Turrell. Photo: Courtesy the Stedelijk Museum In the work Remagin of 2002, the light defines virtual planes that make up a three-dimensional space by the illusion of depth and perspective. The space acts as a stage, as a panel su- pport or canvas which capture a virtual image. In these approaches, the light, the space and the observer are es- sential, without them it is possible to complete the work. The projections in the urban space require water surfaces, the facades of the buildings or the pavements of the city as a material to be seen from the sky or clouds. Artists such as Rafael Lozano He- mmer, Jeny Holzer and Jan Kersalé. construct messages and pictures over- laid to the architecture, or just chroma- tic varnish on its outer skin. 3. Psychological interaction. Per- ceptual light. Color and saturation Once overcome the physical or per- ceptual object, the Light Art moves towards the emotional exploration of the subject. Experiment with the psychological interpretation, with the game between the qualities of the light and the sensory perception, whether to transform or to investigate the physio- logical sensation of space. Green Light Corridor, or Yellow room triangular, by Bruce Neumann, are examples of that. These experiences lose their strength when they move to an architectural space due to the weight of the archi- tecture. Chromatic relationships are more complex by the presence of the materials themselves. Strengthening and chromatic nullification play a role in the perception of the work, which is perceived as an added facility, rather than a bet of light transformation of the ambient. Works as: Neon-723 657, by Dan Flavin; Truism Y by Jeni Holzer, The Wedgeworks by Turrell; Room for one colour and 360 ° room for all colours, by O. Eliasson, are significant although the perceptual Cells or Ganzfeld Sphere by J. Turrell where the approaches are strictly sensory being the observer fa- cing light without any physical referen- ce of space. The purpose of this works is not to change the perception of space, but to The works of Dan Flavin in the seven- ties, consisting of modular structures of fluorescent tubes, begin to relate with the space to maintain a role ‘figure and container’ without trying to change it. Other types of objects are the ones constructed with light, they are geome- tric shapes or spaces which are percei- ved from a two-dimensional represen- tation. They are the Afruns by James Turrell, made of light projections on different surfaces. In this case the work is a purely cog- nitive exercise. The light is the means to realize a ‘visual image’ built mentally as three-dimensional. The space is not involved in the work. This is a visual comprehension exercise, a game of light and visual perspective. The works also move to the urban space. Often, artists are based on natural elements, such as the proposed Tree of light, by Francesco Destefa- no, or explore the visual impact of an object defined by lines of light optical fiber, as in the work Canoe by Warren Langley. Sometimes the repetition of the luminous object fills the space and transforms the work into a global inter- vention of landscape character as in the proposals of Christo and Chris Burden. Also the work approaches architectu- re as in the case of the artist Brigitte Kowanz. In these proposals, the light is intrin- sically linked to the physical object. It is retained therein lighting the space without trying more than the mere observation of the object. However when the light needs the space to complete the vision of the work, and to materialize it we are not facing objects but projections. 3. Light Projections That means that through spots of di- fferent luminance and geometric shape compose, on a visual perspective, a deep space and materialized. Unlike the Afruns by Turrell, the projections of O. Eliasson explore with its transparency, the virtual definition of a space boun- ded by solid and translucent planes simultaneously.