visibility level [FVL]

ratio to indicate how much the contrast of the target is above threshold contrast, based on the formula

        FVL = ΔLactual / ΔLthreshold


ΔLactual is the real difference in luminance between the target and its background

ΔLthreshold  is the luminance difference needed between a target of a certain angular size and its background for the target to be just visible, that is at the threshold

Unit: 1

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer