Comparison of Procedures for Measuring the Temporal Contrast Sensitivity Function

The IEC voltage flickermeter and light flickermeter are algorithms used to estimate the severity of flicker produced by artificial lighting systems. The algorithm was developed around incandescent lamps. In an effort to revise and update the algorithm to be compatible also with LED lamps, the flicker sensitivity curve needs to be verified with white light produced by LEDs, which have a distinct spectrum.This paper is concerned with comparing two distinct approaches to measure the flicker sensitivity of human observers. Traditionally, the flicker sensitivity (Temporal Contrast Sensitivity Function – TCSF) is measured by the Method of Adjustments, where the observer adjusts the stimulus intensity until they are satisfied with finding the flicker visibility threshold. In this paper, the method is compared to Two Alternative Forced Choice tests driven by a dynamic QUEST algorithm in terms of accuracy, speed, friendliness towards the observer, and the information yield in general.