A Pilot Study Assessing Short-Term Chromatic Adaptation Preferences for Correlated Colour Temperature in India

Abstract

This small-scale pilot study investigates peoples’ shortterm chromatic adaptation preferences for correlated colour temperature (CCT) within the cultural context of India. White tone CCT preferences were investigated using a spectrally tuneable LED lighting system. A mock-up room was built and illuminated with two LED luminaires. Each LED luminaire has 216 clusters and each cluster comprising three LED with CCT equal respectively to 3000 K, 4000 K and 6500 K (total 648 LEDs per luminaire). User preference studies in a generic environment were conducted with 50 Indian subjects, where each subject performed generic everyday activities, such as reading, watching TV, eating and relaxing, while being totally immersed in three different scenes of 3000 K, 4000 K and 6500 K. The study shows 6500 K is the least preferred CCT, and 4000 K is preferred for task-oriented activities such as reading and eating. Furthermore, subjects are unable to differentiate between 3000 K and 4000 K while performing non-task-oriented activities such as relaxing and watching TV.