The role of the eye in high-speed motion analysis

Prior to the invention of the photographic process over 150 years ago, the analyses of rapid motions were limited by the dynamic efficacies of the human eve, which has a temporal resolution of similar to 1/10 sec and a maximum information acquisition rate estimated at 10(3) to 10(4) bits/sec(1). At high rates of object motion, only the simplest actions can be resolved, comprehended and retained in human memory. Advances in the field of high-speed photography drastically changed all this by providing us with the ability today to capture permanent images of transient events at acquisition rates in excess of 10(12) bits/sec. As remarkable as these improvements in temporal resolution and image retention may be, the final step in correctly interpreting and image still rests largely upon the analyst's ability to process visual data. Those who enter the field of image analysis soon learn how capricious the eye can be in this task. It is incumbent upon anyone performing important image analyses to have al least a basic understanding of the eye's performance characteristics, especially its limitations and capricious anomalies. Exemplary data presented in this paper are drawn from the scientific literature and the author's forty years of experience as a researcher, author and educator in the field of high-speed imaging.