A dual-beam polariscope for obtaining simultaneous normal and oblique incidence photoelastic stress patterns was recently designed for use with a high-speed framing camera. Dynamic stress patterns were photographed at speeds up to 720,000 frames per second using flashtubes and filters to obtain monochromatic light. The equipment and techniques are described and pre-liminary results are given.

The mammalian visual system evolved as a detector of information in the three-dimensional world. Data are presented which indicate that, with a two-dimensional presentation such as a printed page or screen, the optic tracts which normally carry Z-axis information serve merely as visual noise. Optical means were employed to delete the information from these tracts, and improved operator performance resulted. With or without this deletion, certain observer categories showed greatly superior performance, such that these observers should be utilized for particularly critical monitoring tasks. A simple test battery was developed having predictive value for selection of these observers.

It is the objective of this discussion to present a mechanism for the appraisal of the performance of optical systems. In order for such a mechanism to be of value, it must be based on reasonable theoretical concepts and be so composed as to permit straightforward, easily interpreted physical measurements. These requirements are necessary so that a body of theory will exist which can predict with reasonable accuracy the results of experiment and the performance of actual systems. It is not our intention in this discussion to delve deeply into the theory, to go into extensive discussions of experiments and results, or to provide numerous comparisons of prediction and performance on actual optical systems. On the other hand, we will try to cover the salient features of the theory and its experimental support, as well as some insight into the practical aspects of mechanism.