Compression of visual space in natural scenes and in their photographic counterparts

Classical theories of space perception posit continuous distortions of subj ective space. These stand in contrast to the quantitatively and qualitative ly different distortions experienced in space that is represented pictorial ly. We challenge several aspects of these theories. Comparing real-world ob jects with depictions of the same objects, we investigated to what extent d istortions are introduced by the photographic medium. Corners of irregularl y shaped buildings had to be judged in terms of the vertical dihedral angle s subtended by two adjacent walls. Across all conditions, a robust effect o f viewing distance was found: Building corners appear to flatten out with d istance. Moreover, depictions of corners produce remarkably similar results and should not receive a different theoretical treatment than do real-worl d scenes. The flattening of vertical angles cannot be explained by a linear distortion of the entire visual space. We suggest that, for natural scenes , compression of space is local and dependent on contextual information.