Stretching Perceptual Boundaries in Confined Interior Volumes The Effects of Photometric Parameters on Spatial Depth and Psychological Comfort

Global urbanization dynamics, population growth, and shifts in the real estate economy have led to the proliferation of "micro-volume" typologies in modern residential and commercial architecture. Mitigating the sense of "spatial tightness" and "oppression" created by these spaces, which are restricted in terms of physical boundaries (square footage and ceiling height), has become one of the most critical problems in contemporary interior architecture. This study investigates the use of lighting design as a "perceptual manipulation tool" in confined volumes where physical boundaries cannot be stretched. The research is structured within the framework of John Flynn’s "visual impression modes," Kruithof’s "comfort curve," Gibson’s theory of "ecological perception," and Gestalt principles. Within the scope of the study, the correlation between the parameters of Luminous Intensity, Uniformity Factor, Brightness, and Correlated Color Temperature (CCT) with depth perception was analyzed. In this context, three different scenarios—traditional lighting, incorrect spectral selection, and lighting arrangements providing perceptual expansion—were applied in a corridor space with identical dimensions. Scenario analyses determined that vertical plane illumination is statistically more determinant in volume perception than the horizontal plane ; the 4000K-5000K spectral range pushes back restricted boundaries through the "atmospheric perspective" effect; and a high uniformity ratio reduces visual noise.