We examined the effects of convergence and viewing distance on perceived depth of phantom and conventional stereopsis. Three stimuli were Gillam and Nakayama’s (1999) and Liu et al.’s (1994) phantom stereograms, and RDS. In Experiment 1 and 2, the perceived depth was measured as a function of the convergence angle (4°, 8°, 12°, 16° and 20°) and the size of unpaired region (0.4, 0.7 and 1.0mm) while the viewing distance was held constant. In Experiment 3, the perceived depth was measured as a function of the viewing distance (60, 80, 100, 120 and 140 cm) and the size of unpaired region (1.6, 1.8 and 2.0mm). The results of the three experiments showed that: (a) the magnitude of perceived depth increased as the convergence angle decreased and (b) when convergence and the viewing distance covaried, the depth scaling by convergence information became more effective for both phantom and conventional stereopsis. We conclude that both the phantom and conventional stereopsis have similar processes to scale apparent depth by convergence or the viewing distance information.

In recent years experimental interest in motion parallax has increased, following the rediscovery of the idea to yoke stimulus motion to head movement. Moreover, definitions of motion parallax are included in most introductory textbooks of perception, but they are not all in accordance. We compare the definitions with contemporary research, which indicates how depth and motion perception are dependent on the conditions of stimulation.