Aim: Subjects with no clinically measurable stereoacuity report compelling ‘pop-out’ depth effects when viewing a 3D stereoscopic video. The purpose of this study was to systematically investigate the effectiveness of static and dynamic stereoscopic stimuli, by isolating cues to depth present in stereoscopic 3D entertainment media.
Methods: Stereoscopic stimuli were developed that either featured or lacked changes of disparity and/or of stimulus pattern. A PC-controlled 4-alternativeforced-choice (4AFC) task was used to assess the depth detection thresholds of visually normal subjects, with stimuli presented on a passive polarised stereoscopic monitor at 3 m. Thresholds were determined in four conditions: baseline STATIC (fixed disparity level), STATIC PATTERN CHANGE (fixed disparity level with a change in stimulus pattern), Z-LOCATION CHANGE (disparity increase towards target level with a fixed pattern) and CDOT (disparity increase with pattern change).
Results: In total 32 subjects aged 18–41 years were recruited from the University of Liverpool. The mean(SD) thresholds were: STATIC 183@(101), Z-LOCATION CHANGE 120@(60), CDOT 167@(111) and STATIC PATTERN CHANGE 241@(129). The conditions which contained a change in z-location yielded a significantly lower threshold than those with fixed disparity ( p > 0.01), whereas the presence of a pattern change resulted in a statistically significant reduction in threshold ( p > 0.05). There was no significant interaction between the factors.
Conclusion: By directly comparing thresholds for static and dynamic conditions using stimuli presented on the same device with the same settings (such as display duration, size, contrast, colour, display method, luminance, testing protocol), we can conclude that it is the dynamic nature of the disparity information that confers a benefit on individuals’ depth detection. The dynamic facet of stereopsis may contribute to the compelling ‘pop-out’ effect described when viewing 3D entertainment media.