The Constancy of Stereoscopic Depth Perception.
Abstract
Depth constancy is said to occur when the apparent depth in a scene remains the same as viewing distance changes. Studies of depth constancy have left unanswered questions regarding the range of viewing distances over which depth constancy can operate and the role of retinal disparity in preserving apparently constant depth. In this study, stereoscopic afterimages were exploited to confront these questions. Afterimages containing depth information in the form of retinal disparity were produced and viewed at various fixation distances. Apparent depth in the afterimage was measured by asking observers to set a depth probe equidistant to the afterimage. This technique permitted holding retinal disparity constant as viewing distance changed. It allowed testing at very large viewing distances in the presence of multiple depth cues. The results indicate that stereoscopic depth constancy can be preserved at viewing distances at least as great as 27 meters (the largest used). These changes were veridical and demonstrate that the relationship between perceived depth and retinal disparity is consistent with the geometry describing stereopsis. These findings set requirements for theories of depth constancy. Specifically, they demand that such theories show how retinal disparity can be correctly recalibrated on the basis of distance information available in the visual array. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 12, 1982
- Accession Number
- ADA111484
Entities
People
- Robert H. Cormack
Organizations
- Vanderbilt University