This paper contributes to existing research by showing the influence of the distribution of light on the perception of a space. It addresses the importance of conceptual awareness and the impact of informants' possible pre-understandings. It combines and develops research methods that can accommodate the complexity of real spaces through patterns and relationships. Additionally, it includes concept development of spatial understanding. This primarily qualitative approach of dealing with complex spaces provides a new and unique contribution to the field of lighting research. This lighting design research consists of experimental studies within three different complex spatial contexts, from scale models to interior and exterior spaces. The importance of visual spatial boundaries and brightness patterns are discussed in relation to enclosure, perceived dimensions and atmosphere. It is more cost effective to make a space more spacious by changing the distribution of light than by changing the physical space through alterations. Light may generally have an enlarging effect, though sometimes it can have the opposite effect. This paper addresses how the placement of luminaires, the direction of light and the focus and spread of the light impact the perceived spatial dimensions and experience of atmosphere. A light zone can include as well as exclude participants. A focused light may call for attention, causing an audience to lower its speaking volume. Distribution of light is also useful for dividing a large office landscape into spatial units. The light topography—the upper boundary created by the heights of luminaires in a space—and light direction are factors of empowerment. A clearly defined, tangible space seems to also contribute to an experience of safety. Illuminated vertical surfaces can contribute to a clear overview and a clearly defined space that is experienced as having a sheltering and embracing effect.