With the prosperity of stereoscopic industry

the disparity-based stereoscopic technology becomes more and more popular.But this technology may bring viewing discomfort and various image distortions such as depth plane curvature

depth non-linearity and so on.To analyze the origins

characteristics and relations of these perceptual issues

we investigated the stereoscopic distortion model and the comfortable viewing zone.This paper first summarized and compared three different configurations of the disparity-based stereoscopic video capturing systems

and focused on the parallel configuration system.The geometry of stereoscopic camera and display systems was presented.The mapping relationship

known as the distortion model

between the camera space and the viewing space was discussed in the parallel-shifting stereoscopic video systems.This distortion model is the basis of the stereoscopic information processing.The shape distortion factor and the depth factor were employed to explain the puppet theater effect and the cardboard effect.The comfortable viewing zone was considered to reduce the problem of visual discomfort and visual fatigue.Its three different representations were compared both qualitatively and quantitatively.At last

the distortion model and the comfortable viewing zone were combined to draw a conclusion of the stereoscopic shooting rules.