IERI: Studies of Loss of Contrast in Visual Tasks Using a Visual and Physical Photometer

Abstract

Many of the results obtained with this test program indicate that simple procedures may not give results on the effect of loss of contrast that are truly meaningful. The visual task evaluator results were disappointing but confirmed the findings that consistency of results varied with different operators. In the author's experiment, a large number of operators making large numbers of readings showed a significant variation which gives further evidence that the operator is a problem.