The effect of stereoscopic filming parameters and exposure duration on quality and naturalness judgements

Previously we reported a study into the effect of stereoscopic filming parameters on perceived quality, naturalness and eye strain. In a pilot experiment, using 25 seconds exposure duration, a marked shift occurred between naturalness and quality ratings as a function of camera separation. This shift was less clearly present in the main experiment, in which we used an exposure duration of 5 seconds. This suggests a potential effect of exposure duration on observer appreciation of stereoscopic images. To further investigate this, we performed an experiment using exposure durations of both 5 and 10 seconds. For these durations, twelve observers rated naturalness of depth and quality of depth for stereoscopic still images varying in camera separation, convergence distance and focal length. The results showed no significant main effect of exposure duration. A small yet significant shift between naturalness and quality was found for both duration conditions. This result replicated earlier findings, indicating that this is a reliable effect, albeit content-dependent. A second experiment was performed with exposure durations ranging from I to 15 seconds. The results of this experiment showed a small yet significant effect of exposure duration. Whereas longer exposure durations do not have a negative impact on the appreciative scores of optimally reproduced stereoscopic images, observers do give lower judgements to monoscopic images and stereoscopic images with unnatural disparity values as exposure duration increases.