Flicker effect of different types of light sources

Author(s):  
Krzyszt Chmielowiec
2008 ◽  
Vol 6 (4) ◽  
pp. 497-504 ◽  
Author(s):  
Elmar Fuchs ◽  
Karl Gatterer

AbstractA colour change of doped YAB crystals and microcrystalline powders takes place upon illumination with different white light sources. This paper presents extensive experimental data on the new materials Ho,Nd:YAB; Ho,Cr:YAB, Nd,Cr:YAB and Ho,Nd,Cr:YAB, resulting in a chart providing the observed crystal colours and chromaticity differences of the materials under illumination with seven different types of white light sources. The microcrystalline powders could be used as coatings in order to produce a special colour changing effect. Furthermore, the colour table presented enables the observer to discriminate the investigated light sources at one glance.


2009 ◽  
Author(s):  
Bob Cameron

It must be appreciated that no building surface is perfectly flat and that the best that can be expected is the appearance of flatness. Unfortunately, this appearance can easily be destroyed by the effect of glancing light, whether natural or artificial. Illumination and Decoration of Flat Surfaces shows the effect of different light sources on a variety of lining materials and paints so that best results can be achieved. Different types of building surfaces are investigated, including set plaster, fibrous plaster, hardboard and gypsum board with gloss and semi-gloss paint applied. This full-colour edition also discusses new building materials such as cement sheet, polystyrene and various composite panels, as well as new building practices, low embodied energy materials and higher energy efficiency of buildings. Illumination and Decoration of Flat Surfaces is a must-have for people involved in the building industry, both commercial and residential.


2019 ◽  
Vol 8 (1) ◽  
pp. 55-65
Author(s):  
Ingo Rotscholl ◽  
Klaus Trampert ◽  
Franz Schmidt

Abstract This paper summarizes selected approaches, to generate spectral ray data for different types of spectrally varying light sources including only angular variable as well as spatial and angular variable sources. This includes a description of their general ideas and applications, the required measurements, and their mathematical concepts. Finally, achieved results for an Red/Green/Blue/White-light emitting diode (RGBW-LED) system are shown. Ray tracing simulations of a spatially and angularly spectral varying LED system combined with a spectrally sensitive optical system are qualitatively and quantitatively compared to a colorimetric far-field measurement of the same system. The results demonstrate the potential and benefits of spectral ray files in general.


Author(s):  
Pratibha Srivastava

Colors have great importance in our lives. Through them we get to know the conditions around us and know the effect of colors. Colors arise from the spectral activities when they meet the spectrum in the human eye. Originally, only seven colors of the rainbow are considered to be the father of colors. These seven colors are red, orange, yellow, green, sky, blue and purple. Human virtue religion has red, blue and green colors according to the virtual perception. Different types of objects, sources and categories etc. come from colors. The physical, properties of light sources such as light villian, inclusion, reflection, etc. are associated with which color combinations are known. रंगों का हमारे जीवन में बहुत महत्व है। इनके द्वारा हमें अपने चारों ओर की स्थितियों का ज्ञान होता है और रंगों का प्रभाव ज्ञात होता है। रंग मनुष्य की आँख में वर्णक्रम से मिलने पर छाया संबंधी गतिविधियों से उत्पन्न होते है। मूलरूप से इन्द्रधनुष के सात रंगों को ही रंगों का जनक माना जाता है। ये सात रंग लाल, नारंगी, पीला, हरा, आसमानी, नीला व बैंगनी है। मानवीय गुण धर्म में आभासी बोध के अनुसार लाल, नीला व हरा रंग होता है। रंगों से विभिन्न प्रकार से वस्तु प्रकाष स्त्रोत एवं श्रेणियां इत्यादि आती है। प्रकाष स्त्रोतोें के भौतिक, गुणधर्म जैसे प्रकाष विलियन, समावेषन, परावर्तन, इत्यादि जुड़े है, जिनसे रंग संयोजन ज्ञात होते है।


Tekstilec ◽  
2021 ◽  
Vol 64 (1) ◽  
pp. 4-15
Author(s):  
Veronika Štampfl ◽  
◽  
Klemen Možina ◽  
Jure Ahtik ◽  
◽  
...  

The research focuses on the quality of colour reproduction when using different light sources, often used to illuminate scenes in a photo studio, and different types of fabrics as lighting shapers. With the latter, the light can be converted into softer and more diffuse light, but the properties of the fabrics used affect the colour impression and thus the quality of the reproduced colours. This was evaluated by analysing the colour differ¬ences which were calculated from the colorimetric values of the colour patches of the X-Rite ColorChecker Passport test chart. Test chart was photographed in a controlled environment and illuminated with different combinations of light sources and tested fabrics. The results confirmed that not all combinations of variables are suitable for use if the goal of the photograph is to achieve high quality colour reproduction.


2020 ◽  
Author(s):  
Francisca Figueira ◽  
Marta Matos ◽  
Aida Nunes ◽  
Mariana Afonso ◽  
Ana Clara Rocha ◽  
...  

Three surveys on the occurrence of foxing stains were carried out on papers dating from 1560 to 1975 in three Portuguese collections. Foxed papers were found to be more intensely and intrusively stained in certain time periods of each collection. Based on historical data and on the professional paper conservation experience, the authors linked the increased occurrence of foxing stains in certain time periods to the new papermaking processes and materials, which began to be introduced in the late 18th century, and in particular to a synergistic effect between three factors: the use of deficient gelatine sizing which began to present a poorer quality and homogeneity, the presence of iron-containing impurities throughout the paper leaf and a distinct sorbency of moisture. Observing batches of morphologically similar papers by using photographic imaging with different types of light sources and incidences, the authors verified that similar papers present similar foxing stains.


2011 ◽  
Vol 2 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Daphne Câmara Barcellos ◽  
Alessandra Buhler Borges ◽  
Carlos Rocha Gomes Torres ◽  
Graziela Ribeiro Batista

ABSTRACT Purpose This study evaluated the temperature of the pulpal chamber (PC) of teeth submitted to the light activation with and without bleaching gel, using different types of light sources. Materials and methods A digital thermometer, thermocouple K type, was located in the PC of human upper central incisors and the specimens received light activation from the following sources: G1—Laser, G2—Halogen light, G3—progressive intensity halogen lamp, G4—LED/Laser. The light was applied for 3 minutes, with and without the use of bleaching gel. The data were collected after every 30 seconds and analyzed by three-way ANOVA and Tukey's test. Results The mean values were: Use of the gel—with gel: 3.09a, without gel: 2.79b; Type of light source—G1: 0.60a, G2: 2.38b, G3: 4.16c, G4: 4.63d; Time of activation 30 seconds: 1.15a, 1 minutes: 2.20b, 1 minutes 30 seconds: 2.97c, 2 minutes: 3.44d, 2 minutes 30 seconds: 3.81e, 3 minutes: 4.09e. Conclusions The use of bleaching gel associated with light activation resulted in higher heating of the PC. LED/LASER light and progressive intensity halogen lamp showed highest levels of heating. The increase of irradiation time significantly increased the temperature.


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