Put the Light Where it is Needed

Abstract: In this thesis I have analyzed how the phenomenon level of contrast, a consequence of the relation between level of light and distribution of light, works within urban green areas. For this particular site, the too high level of contrast is a result of the high level of light distributed 1) in the direction of oncoming pedestrians and 2) in a single zone of light and 3) on a too condensed surface area and 4) in a space with multiple vertical elements (in a dark space with low reflectance values). Being in the only lighted area surrounded by trees (vertical elements absorbing or reflecting light), with eyes adapted to its level of light, consequently, makes it impossible to see beyond the path. This since our eyes always adapt to the brightest spot in our field of view, which in all directions is a spot very close to the user. And since adapting to the emitted and reflected light our eyes cannot also adapt to the darkness beyond this enclosed space. Another perspective on this, also related to the very basics of our vision has to do with the task oriented lighting solutions. We humans have two different types of vision - central and peripheral. The central vision is approximately 2% of our field of view, it is the small spot where our gaze focus, the rest is peripheral vision. The strange thing is that modern urban lighting design have focused almost solely on task lighting and the central vision, and left the peripheral vision literally disorientated. Because, in order for the peripheral vision to help us navigate and collect spatial information, it needs variable lightning with multiple zones of light, creating differences in shade, revealing form and depth. The main contribution of this thesis, beyond defining knowledge regarding how light acts in these specific situations, is the development of a lighting design method specifically for urban green areas from a practice based design perspective (see figure 16). And that I have started the work of creating practical knowledge and answers to the question: How can the method be used in practice?