Subjective responses to display bezel characteristics

© 2015. This manuscript version is made available under the CC-BY-NC-ND 4.0 licensehttp://creativecommons.org/licenses/by-nc-nd/4.0/High quality flat panel computer displays (FPDs) with high resolution screens are now commonplace, and black, grey, white, beige and silver surrounds (‘bezels’), matt or glossy, are in widespread use. It has been suggested that bezels with high reflectance, or with a high gloss, could cause eyestrain, and we have investigated this issue. Twenty office workers (unaware of the study purpose) used six different FPDs, for a week each, at their own desk. These displays were identical apart from the bezel colour (black, white or silver) and shininess (matt or glossy). Participants completed questionnaires about their visual comfort at the end of each week, and were fully debriefed in lunch-time focus groups at the end of the study. For the white and the silver bezels, the glossiness of the bezel was not an issue of concern. The participants were significantly less content with the glossy black surround than with the matt black surround, and in general the glossy black bezel was the least-liked of all those used. With the possible exception of this surround, there was no evidence of significantly increased visual discomfort, indicative of eyestrain, as a result of high or low bezel reflectance, or of high glossiness

Final report on the CCPR Key Comparison CCPR-K3.2014 Luminous Intensity

Main text The metrological equivalence of national measurement standards in the field of photometry and radiometry is determined by a set of key comparisons chosen and organised by the Consultative Committee of Photometry and Radiometry (CCPR) of the Comité international des poids et mesures (CIPM), working closely with the Regional Metrology Organisations (RMOs). In September 2009 the CCPR decided that a second round of the key comparison K3 Luminous Intensity be commenced. The National Research Council of Canada (NRC) was chosen to pilot this comparison. A total of 12 participants were selected from the three RMO group members: EURAMET&COOMET (6: IO-CSIC, LNE-CNAM, METAS, NPL, PTB, VNIIOFI), APMP&AFRIMETS (4: NMISA, NIM, NMIA, NMIJ), and SIM (2: NIST, NRC). The comparison was organised as a star comparison (NMI-Pilot-NMI) using incandescent standard lamps supplied by each NMI (National Metrology Institute) as the travelling comparison artifact. This report describes the comparison organisation (Section 2), the measurement methods and uncertainties achieved at all the participants and at the pilot (Sections 3 and 4), and the method for analysis and the results of the comparison according to this method (Section 4). It includes a comparison of the results of this comparison with the 1999 first round key comparison (Section 5). Section 6 presents a summary of the comparison. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA)

Intercomparison of bidirectional reflectance distribution function measurements at in- and out-of-plane geometries

10 pags., 8 figs., 5 tabs.In recent years, there has been a growing interest in the measurements of the bidirectional reflectance distribution function (BRDF) in industry and research and development. However, there is currently no dedicated key comparison to demonstrate the scale conformity. To date, scale conformity has been proved only for classical in-plane geometries, in comparisons between different national metrology institutes (NMIs) and designated institutes (DIs). This study aims at expanding that with nonclassical geometries, including, for the first time, to the best of our knowledge, two out-of-plane geometries. A total of four NMIs and two DIs participated in a scale comparison of the BRDF measurements of three achromatic samples at 550 nm in five measurement geometries. The realization of the scale of BRDF is a well-understood procedure, as explained in this paper, but the comparison of the measured values presents slight inconsistencies in some geometries, most likely due to the underestimation of measurement uncertainties. This underestimation was revealed and indirectly quantified using the Mandel-Paule method, which provides the interlaboratory uncertainty. The results from the presented comparison allow the present state of the BRDF scale realization to be evaluated, not only for classical in-plane geometries, but also for out-of-plane geometries.This work has been done in the frame of the EMPIR project 18SIB03 (BxDiff ) that has received funding from the EMPIR programme co-financed by the participating states and from the European Union’s Horizon 2020 Research and Innovation ProgrammePeer reviewe

Multilateral spectral radiance factor scale comparison

The field of spectral radiance factor (SRF) measurements has seen growing interest in recent years. Scale conformity has so far only been established between the national metrology institutes (NMIs) of Germany and the USA. This study aims at a bigger, multilateral scale comparison. For this purpose, a total of six NMIs participated in a scale comparison of goniospectrophotometers based on neutral and colored diffusely reflecting ceramics samples. In addition, two universities, providing a home-built gonioreflectometer and two widely used commercially available color measurement instruments, respectively, were involved. The wavelength range of the scale comparison covers the visible wavelength range from 380 nm to 780 nm. Results indicate systematic issues and that the uncertainty evaluation of the NMIs requires further work; although for the greatest part of the covered spectral range the agreement is good

Multilateral spectral radiance factor scale comparison

11 pags., 11 figs., 3 tabs., app. -- OCIS codes: (290.1483) BSDF, BRDF, and BTDF; (120.1840) Densitometers, reflectometers; (120.5700) Reflection.The field of spectral radiance factor (SRF) measurements has seen growing interest in recent years. Scale conformity has so far only been established between the national metrology institutes (NMIs) of Germany and the USA. This study aims at a bigger, multilateral scale comparison. For this purpose, a total of six NMIs participated in a scale comparison of goniospectrophotometers based on neutral and colored diffusely reflecting ceramics samples. In addition, two universities, providing a home-built gonioreflectometer and two widely used commercially available color measurement instruments, respectively, were involved. The wavelength range of the scale comparison covers the visible wavelength range from 380 nm to 780 nm. Results indicate systematic issues and that the uncertainty evaluation of the NMIs requires further work; although for the greatest part of the covered spectral range the agreement is good.This work has been realized within the European Metrology Research Program (EMRP) project JRPIND52. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. We thank the European Commission and EURAMET e.V. for financial support.Peer Reviewe

¿Es necesario normalizar la medida de la BRDF?

XII Congreso Nacional del Color, Linares, 25 al 27 de septiembre de 2019. -- https://www.baobabeventos.com/xiicncEl éxito comercial de un producto depende a menudo de su aspecto estético. Por esta razón, diferentes sectores industriales, como el de recubrimientos para automóviles, los cosméticos, o los materiales impresos para empaquetado, buscan continuamente nuevos efectos visuales atractivos: gonio-cromatismo, translucidez, destello, etc. La magnitud relevante para la medida de estos atributos perceptivos es la Función de Distribución Bidireccional de Reflectancia (BRDF), que informa sobre la luz reflejada por una superficie y, por tanto, sobre la apariencia visual de un producto. Las normas actuales de medida del color (ISO 11664) y del brillo (ISO 2813) no son válidas para la caracterización de efectos visuales complejos. Solo algunas normas ASTM fijan un conjunto de geometrías de medición para estos efectos, pero no existe una norma para la medida de BRDF que caracterice totalmente esos efectos. Tras haber realizado esfuerzos metrológicos significativos para mejorar la medida de la BRDF, particularmente a nivel europeo gracias al proyecto ¿Multidimensional reflectometry for Industry¿ (EMRP IND52, xDReflect), se ha puesto en marcha otro proyecto europeo ¿Bidirectional reflectance definitions¿ (16NRM08, BiRD) que pretende apoyar a las organizaciones normativas en la estandarización de la medida de BRDF. Los objetivos de este proyecto que se presentan en esta comunicación son: ¿ Realizar una guía de buenas prácticas de medida de la BRDF teniendo en cuenta el tipo de muestra y la necesidad de la medida, que será puesta a disposición del Comité Técnico TC 2-85 de la CIE, como primera etapa para la normalización de medidas de la BRDF. ¿ Desarrollo de un formato universal para la comunicación digital de medidas de BRDF. ¿ Propuesta de un nuevo método de medida de brillo relacionado con la percepción visual. ¿ Propuesta de una definición consensuada de destello (¿sparkle¿) y granularidad (¿graininess¿) y de los procesos de medida correlacionados con esas sensaciones visuales

¿Es necesario normalizar la medida de la BRDF?

3 pags.Los autores agradecen al programa EMPIR por la subvención del proyecto “Bidirectinal refletance definitions” (BiRD). EMPIR es una iniciativa financiada conjuntamente entre el programa de investigación e innovación “Horizonte 2020” de la Unión Europea y los países miembros de EMPI

Data File 1: Multilateral spectral radiance factor scale comparison

Measurement data of the spectral radiance factor including the uncertainty Originally published in Applied Optics on 01 March 2017 (ao-56-7-1996