Browsing by Subject "Correlated Color Temperature"

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Open Access
The Effects of correlated color temperature on sustained attention and mood of university students in learning environments
(2015) Kocaoğlu, Rengin
The aim of this study is to understand the effects of correlated color temperature on sustained attention and mood of university students in learning environments and to compare different color temperatures. The experiment was conducted with two different sample groups in two different lighting settings; 4000 K and 6500 K in a single phase. The participants were ninety seven undergraduate students from Bilkent University. The participants were seated in a regular lecture room and tested by the researcher. They were asked to perform three paper- based tests; one of them about the sustained attention, d2 Test of Attention, and the other two about mood, (PANAS) Positive and Negative Affect Schedule. It was found that correlated color temperature has no significant effect on concentration performance, errors of omission, total numbers of items processed. A certain conclusion could not be derived about the effect of color temperature on mood. However, color temperature has a significant effect on errors of commission and number of errors. It was found that 4000 K significantly increases errors of commission and number of errors, thus 6500 K is more appropriate for university learning environments.
Open Access
The impact of art object color and style on museum visitors’ correlated color temperature (CCT) light preferences
(2018-05) Emirtekin, Tuna Zişan
The aim of this study is to understand the effect of art objects’ color and style on museum visitors’ CCT light preferences. In order to analyze both color and style of art objects’ effect on museum lighting preference, a small exhibition room was designed. The study was conducted with three sample groups for three styles of paintings. Those styles were still life paintings, drip paintings and contemporary figurative art paintings with three color schemes for each style which are blue, red and neutral. Three CCT of light were used in the experiment which are 3000 K warm white, 4000 K neutral white and 6000 K cool white LED spots all at 200 lux illuminance. Besides the CCT preference, participants were asked to evaluate factors that would appropriately describe the exhibited objects, painting color and lighting relations. Those evaluative factors were warmth, brightness, comfort, pleasantness, naturalness and relaxation. The results showed that most preferred CCT of light was 4000 K for all styles and colors. The general indication that could be done about the CCT preference results is that visitors want to see warm color paintings under lower CCTs while in case of cool color paintings the choice of visitors are towards higher CCTs. This preference tendency is the most significant on paintings that have facial depictions. According to the evaluative emotional states results, for all bipolar adjectives both color and CCT have an impact. The results of the study can be beneficial for museum curators, lighting designers and interior architects while designing a museum environment.
Open Access
A photometric investigation of ultra-efficient LEDs with high color rendering index and high luminous efficacy employing nanocrystal quantum dot luminophores
(Optical Society of America, 2009-12-24) Erdem, T.; Nizamoglu, S.; Sun, X. W.; Demir, Hilmi Volkan
We report a photometric study of ultra-efficient light emitting diodes (LEDs) that exhibit superior color rendering index (CRI) and luminous efficacy of optical radiation (LER) using semiconductor quantum dot nanocrystal (NC) luminophores. Over 200 million systematically varied NC-LED designs have been simulated to understand feasible performance in terms of CRI vs. LER. We evaluated the effects of design parameters including peak emission wavelength, full-width-at-half-maximum, and relative amplitudes of each NC color component on LED performance. Warm-white LEDs with CRI >90 and LER >380 lm/W at a correlated color temperature of 3000 K are shown to be achieved using nanocrystal luminophores. (C) 2009 Optical Society of America