The phantom array effect, also known as ghosting, is one of the temporal light artefacts caused
\nby temporally modulated light systems.<\/p>\n
In this study, the visibility of the phantom array effect
\nunder indirect viewing office lighting conditions was tested to verify whether it can cause a
\nproblem when making saccades across words during reading.<\/p>\n
Results show that, under a very
\ncritical condition of a white target on a black surface, the phantom array effect is easily
\nperceived, especially at the intermediate frequency of 600 Hz.<\/p>\n
But under the normal reading
\ncondition of a black target on a white surface, the phantom array effect becomes very difficult
\nto detect.<\/p>\n
Temporal light modulation, (TLM) of lighting systems is known to affect human visual
\nperception, neurobiology, and performance.<\/p>\n
This experiment measured Stroop cognitive
\nperformance, reading performance, eye movements, discomfort, and phantom array
\nperception during exposure to each of nine TLM conditions chosen to contrast conditions
\nvarying in TLM frequency, modulation depth, or duty cycle and based on predictions drawn
\nfrom the IEEE S1789-2015 recommendations.<\/p>\n
Data from 50 adult participants aged 18-65
\nrevealed small effects mostly in predicted directions.<\/p>\n
The results support the recommendation
\nthat lower modulation depths are preferable over higher, and add to our knowledge by
\nshowing that duty cycle could also influence outcomes and that the phantom array can be
\ndetected under photopic conditions.<\/p>\n
This underlies the importance of taking a lighting
\nsystems approach to studying TLM and considering a range of effects.<\/p>\n
Future research
\nshould increase statistical power by increasing task difficulty, and duration of exposure.<\/p>\n
More
\nnaturalistic viewing conditions, such as a greater range of eye and head motion, would
\nimprove the generalizability of the work.<\/p>\n
This study aimed to investigate colour appearance in virtual reality (VR).<\/p>\n
A total of 35 test
\ncolours were visually assessed in a VR space by 16 observers in terms of lightness,
\ncolourfulness and hue quadrature.<\/p>\n
The experimental results show high correlation between
\nperceived colour appearance and predicted values by CIECAM02, with a correlation coefficient
\nof 0.96 between perceived lightness and CIECAM02 J, 0.99 between perceived hue quadrature
\nand CIECAM02 H, and 0.88 between perceived colourfulness and CIECAM02 M.<\/p>\n
Intense blue spectral light components pose a short-term risk to the retina, called blue light
\nhazard (BLH).<\/p>\n
For this photochemically-induced retinal injury spectral weighting functions and
\napplicable limit values are established.<\/p>\n
However, scientific evidence about blue light as a
\nlong-term risk factor promoting age-related macular degeneration (AMD) is less descriptive.<\/p>\n
Some studies indicate that a spectral weighting function seems to be similar to the function
\nused for BLH.<\/p>\n
However, there are some scientific papers reporting good therapeutic results in
\npatients with AMD by the use of a therapy called \u201cphotobiomodulation\u201d.<\/p>\n
This indicates that red
\nand near infrared (NIR) spectral components could be beneficial by counteracting blue light
\ninduced AMD.<\/p>\n
In order to describe the balance between the risk potential of blue and the
\nprotection potential of red\/NIR spectral components an \u201cAMD protection index\u201d is proposed
\nand is applied to various spectra of light sources including LEDs for comparison.<\/p>\n
Light exposure elicits numerous effects on human physiology and behaviour, such as better
\nalertness and mood.<\/p>\n
Here we investigated the effects of natural eye light exposure before
\nawakening on sleep quality and morning alertness and mood.<\/p>\n
16 subjects from 4 dormitories in
\nthe same class of Tsinghua University were selected to conduct a 30-day field experiment in
\nsummer.<\/p>\n
Because of the different distance from the window and the wall shelter, the distribution
\nof natural light in the 4 beds of dormitory in the morning is also different.<\/p>\n
The natural eye light
\nexposure before waking up was obtained by a wireless probe, which could record illumination
\nin real-time.<\/p>\n
The physiological and psychological indicators such as sleep quality at night,
\nalertness and mood after waking up were obtained by questionnaires and sleep monitoring band.<\/p>\n
The results showed that the more the LEA before waking up, the better alertness and mood
\nafter waking up.<\/p>\n
But no significant correlation was found between sleep quality and LEA.<\/p>\n
Substantial efforts have been made to investigate how light source color rendition affects color
\npreference.<\/p>\n
It has been widely agreed that a source with a high color fidelity score may not
\nresult in higher color preference, as a higher saturation is generally preferred.<\/p>\n
Two
\npsychophysical experiments were designed to investigate the color preference of an artwork
\nunder nine nearly metameric stimuli with a gamut area (i.e., IES Rg) between 99 and 124 across
\na wide range of illuminance levels (i.e., from 20 to 15000 lx), which was never carefully studied
\nbefore.<\/p>\n
These different Rg values of the stimuli were designed to be produced by systematic
\nchanges in IES TM-30 red and green chroma shifts.<\/p>\n
The findings revealed that the light level
\nhad a significant impact on color appearance and color preference, with a stimulus having a
\nlarger gamut area being preferred under a lower illuminance level.<\/p>\n
It suggested that light level
\nshould be considered when specifying light source color rendition.<\/p>\n
Due to their potential use as an internal reference, memory colours have proven to provide an
\nexcellent conceptional approach for the colour rendition evaluation of white light sources in
\nterms of predicting visual appreciation.<\/p>\n
However, there are still some major drawbacks that can
\nbe identified in the principal design of existing memory-based or memory-related colour quality
\nmetrics.<\/p>\n
For this reason, a new experiment was devised trying to overcome the shortcomings
\nof these previous approaches.<\/p>\n
Based on the experimental output, the main goal of the current
\nstudy consequently was to derive an improved version of a memory-based colour quality metric,
\nwhich provides a superior tool for developers and manufacturers that can be used for the
\noptimization of state-of-the-art lighting solutions in cases where visual appreciation and high
\nuser acceptability are more important than colour fidelity.<\/p>\n
An experiment is reported showing the dependency of sparkle and glare perception on
\nluminance and area of a light source.<\/p>\n
The experimental conditions are chosen such that the
\nresults can be applied to design aesthetically pleasant LED sources.<\/p>\n
Similar to results of
\nprevious studies, probabilities of sparkle and glare perception are conveniently expressed in
\nthe luminance-area parameter space.<\/p>\n
In recent years a Predictable Quantum Efficient Detector (PQED) has been developed by a joint
\nEuropean effort in the framework of the EUROMET iMERA+\/EMRP programs.<\/p>\n
The PQED
\nconsists of two custom-made induced junction Silicon photodiodes in a wedge trap
\nconfiguration.<\/p>\n
The most notable property of this type of detector is that its external quantum
\nefficiency (EQE) value in the spectral range from 400nm to 850nm is dependent only on
\nfundamental constants.<\/p>\n
The PQED is therefore potentially an ideal candidate for a new primary
\nstandard for optical radiometry in the visible range.<\/p>\n
A considerable effort has been spent to
\nvalidate the absolute value of the PQED spectral responsivity against the current standard for
\noptical radiometry, the cryogenic radiometer, with standard uncertainty below 100 ppm.<\/p>\n
The
\naim of this work is to investigate the PQED long term temporal stability when operated at room
\ntemperature.<\/p>\n
Parking lot lighting should meet multiple objectives.<\/p>\n
One important design objective is that
\nparking lot lighting should provide a sense of personal safety and security.<\/p>\n
This objective has
\nbeen the focus of studies from the Lighting Research Center since the 1990s, which involved
\nresearch on lighting characteristics such as the average illuminance, the spectral power
\ndistribution of the light source, and the uniformity of illumination across the parking lot
\nsurface.<\/p>\n
Building upon this body of research, a recent study is described in which the
\ninteractions among these factors, not only their isolated impacts, on subjective perceptions of
\nsafety and security are assessed.<\/p>\n
The research efforts described here demonstrate how light
\nlevel, spectrum and uniformity combine to affect perceptions of safety in parking lot users.<\/p>\n
Importantly, specifications of lighting based on these criteria would permit substantial
\nreductions in energy use and light pollution in outdoor lighting while meeting users' needs.<\/p>\n
: Safety and Security, Visual Performance, Exterior Lighting<\/p>\n
The goal of the study was to investigate the effects of human centric lighting on the users via
\nboth objective measurements and subjective questionnaires in a real working environment with
\nthe participation of industrial employees.<\/p>\n
During the experimental sessions, heartrate of the
\nparticipants had been monitored and the questionnaires periodically had to be filled out,
\nassessing the participants\u2019 experiences about the experimental lighting.<\/p>\n
The results of the
\nstatistical analyses of the questionnaires clearly show a connection between circadian effects
\nof the human centric lighting\u2019s continuously changing light settings and the participants\u2019
\nsubjective feeling of alertness and their preferences.<\/p>\n
The effect of lighting had been proven
\nusing objective measurements besides the questionnaires.<\/p>\n
A significant moderate correlation
\nbetween the circadian effect and the heartrate changes had been shown.<\/p>\n
The moderate strength
\ncan be acknowledged to other factors which influence the heartrate.<\/p>\n
Hunt Effect is a phenomenon in which object colours at low light levels are perceived less
\nsaturated compared to that at higher light levels.<\/p>\n
If this effect is effective at normal indoor
\nlighting levels, increasing the chroma saturation level at indoor lighting to some extent would
\nmake colour appearance of objects closer to that under outside daylight, thus bring higher
\nfidelity of colours.<\/p>\n
To verify whether the Hunt Effect is effective at normal indoor lighting,
\nvision experiments were conducted using a spectrally tuneable lighting facility simulating a
\nreal size interior room.<\/p>\n
Observers viewed real fruits and vegetables and their skin tones under
\ndifferent chroma levels in red-green direction at illuminance levels of 100 lx and 1000 lx, and
\nevaluated naturalness of these targets.<\/p>\n
The results showed significant differences between
\n100 lx and 1000 lx; subjects perceived objects as most natural at less chroma level at 1000 lx
\nthan at 100 lx.<\/p>\n
The studies on visibility of traffic sign, yellow raincoat and yellow helmet on an experimental
\nroad for dynamic road-lighting in a foggy environment were performed.<\/p>\n
We used an image
\nluminance measuring device to measure the luminance images.<\/p>\n
The analysis of the
\nexperimental results were obtained by the defined contrast ratio and the threshold of fog index.<\/p>\n
The visibility of objects in HPS and LED lighting in the foggy environment can be analysed.<\/p>\n
: Traffic sign, Fog, Contrast Ratio, Dynamic road-lighting<\/p>\n
Glare is a key factor that influencing the visual performance in light conditions of airplane
\ncockpit, and intensity and layout of glare sources in cockpit are extraordinarily complex.<\/p>\n
This
\nstudy investigates the relationship between complex glare sources and discomfort glare
\nevaluations of luminous environment in airplane cockpit.<\/p>\n
Different glare indices are proposed
\nto predict the level of discomfort glare in the cockpit environment with non-uniform glare sources
\nand irregular shape glare sources.<\/p>\n
The result shows the DGP can predict the visual comfort
\nevaluation better than DGI and UGR in complex luminous environments.<\/p>\n
Our previous experiment showed that the Hunt Effect was effective at normal indoor lighting
\nlevels.<\/p>\n
The purpose of this study is to quantify the level of perceived chroma increase by the
\nHunt Effect.<\/p>\n
Two identical colour patches were placed on the left and the right side of the booth.<\/p>\n
The left side of the booth was illuminated at 1000 lx with a broadband spectrum and the right
\nside was illuminated at 100 lx or 300 lx with chroma-increasing lights with different chroma
\nincrease levels.<\/p>\n
Subjects viewed each side of the booth with each eye (haploscopic viewing
\ncondition) and were asked to select a light of the right side that matched the colour of the right-
\nside target closest to the left one.<\/p>\n
Results showed that increased chroma by 15 to 18 in ?C*ab
\nwere needed for the right side to match perceived chroma.<\/p>\n
The chroma increase was smaller
\nat 300 lx.<\/p>\n
In recent years, both the quality of the light environment and the reduction of lighting energy
\nare required in offices.<\/p>\n
To realize these requirements, it is effective to reduce the illumination
\nof background area where occupants are absent while keeping the brightness of the task area
\nwhere occupants are present.<\/p>\n
In this study, we conducted a subjective evaluation of spatial
\nbrightness in a non-uniform lighting environment based on the European standard and in a
\nuniform lighting environment.<\/p>\n
In the experiment, the satisfaction of the whole lighting
\nenvironment was taken as a superordinate concept, and the absolute level of brightness,
\nvisibility, the appropriateness of brightness, and non-uniformity were evaluated as factors
\nexplaining the satisfaction.<\/p>\n
As a result, in the non-uniform lighting environment in conformity of
\nthe European standard, while visibility and absolute brightness levels around desktops were
\nhighly evaluated, the level of satisfaction with light environment was low.<\/p>\n
To identify lighting requirements for ADB systems to help drivers detect off-axis potential
\nhazards when oncoming headlight glare exists in a night-time roadway, we conducted target
\ndetection tests under various experimental conditions in a laboratory.<\/p>\n
In the experiment, we
\nused a simulated ADB system which can illuminate only targets locally and therefore increase
\nthe luminance contrasts of the targets.<\/p>\n
The experimental results suggest that the ADB system
\nis more efficient lighting methods than conventional forward lighting systems which illuminate
\nthe entire visual field to increase drivers\u2019 adaptation luminance levels.<\/p>\n
Based on the detection
\nrates, we also determined requirements for threshold luminance contrast for targets with
\noncoming headlight glare.<\/p>\n
has been conceived to address the analysis of the current nocturnal landscape image, carried
\nout through both qualitative and quantitative analysis.<\/p>\n
In the paper results obtained from the
\napplication of the method to a case study are presented.<\/p>\n","protected":false},"excerpt":{"rendered":"
Proceedings of the 29th Session of the CIE Washington D.C., USA, June 14 \u2013 22, 2019 – Volume 1 – Part 1<\/b><\/p>\n\n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n CIE<\/b><\/a><\/td>\n 2019<\/td>\n 902<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":510762,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2690],"product_tag":[],"class_list":{"0":"post-510755","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-cie","8":"first","9":"instock","10":"sold-individually","11":"shipping-taxable","12":"purchasable","13":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/510755","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/510762"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=510755"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=510755"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=510755"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}