Metal halide (MH) lighting systems are gaining in acceptance relative to high-pressure sodium (HPS) for many night time applications. The present paper describes a series of studies carried out address some the ‘quality’ issues associated with MH and HPS systems. installations were compared terms perceptions brightness safety, acceptability social interaction, facial recognition eyewitness identification. At equal photopic light levels, street scene illuminated at by an system was reliably...

A field study was conducted to extend fundamental findings about visual performance at mesopic light levels a driving context. Subjects participating in this drove vehicle along lighted street while performing high-order decision-making task. identified the direction of an off-axis target, toward or away from street, and braked accelerated, accordingly. Two sets sources were compared: set ceramic metal halide high-pressure sodium sources. The same also performed during day-time. results...

Reducing the peak demand for lighting energy through load shedding can be an effective method of management. However, before such a load-shed technique is applied to real world, it important understand occupants' requirements change in illuminance. Two laboratory studies were conducted better sensitivity and acceptance dimming-memory study dimming curve study. The memory addressed whether one memorize initial illuminance level how long this sustained. investigated effects function on...

This experiment tests the hypothesis that light sources produce smaller pupil sizes ensure better achromatic visual task performance at same photopic illuminance. Two groups of subjects, one in age range 18-28 years and other 61-78 years, performed a Landolt ring for eight different gap sizes, two illuminances, lamp scotopic/photopic ratios. For both groups, size was determined by illuminance spectrum. The speed accuracy size, to much lesser extent, Lamp spectrum had no effect on task.

The study investigated the correlation between subjective glare rating and Unified Glare Rating (UGR). Experiments analyses were carried out. results showed that there was a good UGR indices, but ratings always few units lower than indices. reason for difference them may be simply 'adding up' sensation is not an appropriate way to evaluate discomfort glare. Finally, method proposed modification concerning additivity of

A simulation method to determine adaptation luminance is proposed for implementation of the CIE mesopic photometry system. The takes four factors into account: distribution, eye movement observers, surrounding effect and area measurement. Each factor modelled as a two-dimensional geometrical function. determines an measurement through calculation steps. was applied examples distributions outdoor lit scenes results were compared with possible simple predictors luminance. comparisons suggest...

Reducing the peak demand for electricity by load-shedding techniques can be an effective method of management. Before such a technique is applied to real world, however, it important understand occupants’ illuminance requirements with respect dimming. To identify ability detect and willingness accept reduction, two studies—a bias study lower study—were conducted. In these studies, subjects detected evaluated acceptance dimming while was changed. The informed about importance its potential...

Abstract The variations of eye fixation related potentials (EFRPs) were examined in two tasks under three lighting conditions for assessment environments. Sixteen subjects participated tasks; a difficult and an easy reading task conditions: Spot light (S), General (G) Mixed (M). EEG (Oz) EOG recorded. epochs time-locked to onset fixations collected at random averaged separately arrays obtain pair EFRPs. Two wave forms the S similar, although those G showed disparity, largest disparity being...

This paper discusses a field study which examines headlamp glare. It investigates the role of spectrum, size and illuminance. ascertains relative magnitude each these variables its impact on glare from oncoming vehicles. Results indicate that illuminance at eye level is main factor influences produced by an vehicle.

There is concern that the greater light output and increased beam pattern widths of some headlamp systems may be resulting in higher glare exposures to drivers for longer times. A set experiments described examines how exposure affects recovery time ratings discomfort. Theoretical were examined study different aspects glare, namely peak illuminance total dosage. Glare corresponding representative tungsten halogen (TH) high intensity discharge (HID) also examined. It was found shape profile...

An experiment was performed to investigate the influence of sparkling luminous elements on overall brightness impressions. Evaluations impressions were carried out under various lighting conditions in which luminance, size, shape and background luminance element varied. Subjective appraisals impression (sparkling, glaring or merely bright) also out. The results suggested that a room with is often about 1.2-1.3 times higher than without optimum increased elucidated.

The purpose of this study is to reconsider the optimal lighting conditions in office buildings with respect both occupants' visual comfort and reduced energy use. This paper reports on how Japan changed after events that followed Great East Earthquake March 2011. For first step, a survey facility managers was conducted nationwide. focused specific measures taken reduce power consumption. Additionally, occupants each building filled out questionnaire about their working areas.The results...

Commission Intemationale de l'Eclairage (CIE) published CIE 191: Recommended System for Mesopic Photometry Based on Visual Performance was in 2010. However, it is still necessary to identify appropriate applications and make guidelines the new mesopic photometry system. To this end, we dealt with interference between foveal task peripheral that often exists real driving context. Such appears exaggerate effectiveness of short-wavelength radiation visual performance at light levels. address a...

In ageing societies, it is necessary to make the visual environment more appropriate for elderly so that they can maintain performance as long possible. To this end, we aimed at developing guidelines determine adaptation luminance and contrast given letter sizes elderly. study, first measured sensitivities of older participants. Second, conducted an experiment in which same participants evaluated degrees readability Japanese sentences with various sizes, contrasts luminances. Based on...

This document reports on a field study undertaken to measure peripheral visual performance under various headlamp conditions. The include conditions that are typical of halogen and high intensity discharge (HID) headlamps explored functions could be incorporated in advanced forward-lighting systems (AFS). Targets varying size were located at different locations along the edges both left- right-hand curves, illumination used. Reaction times missed targets measured. authors found benefit...

This paper describes an experiment designed to establish the effect of size, luminance and ambient light level on probability sparkle being perceived when looking at array luminous apertures. From data collected, iso- contours for perception are developed their application demonstrated.

We compared the concentration of subjects under general illumination, where ambient illuminance was equal to task illuminance, with partial lower than illuminance. The level evaluated by subjective appraisals, observations behavior subjects, and measurements lambda responses (a brain response). appraisals showed that found it easiest concentrate on routine office duties but they more intellectually demanding like planning studying illumination. Observations subject clearly could better their...

We compared the concentration levels of subjects under several lighting conditions in which ratio task illuminance to ambient was varied.In order evaluate subjects' concentration, subjective appraisals and measurements lambda responses (one brain's responses) were carried out. The results showed a close correlation between measured responses.We found that from 0.02 0.3 provided optimum for concentration.

Mesopic photometry can be applied to road lighting practice enhance peripheral visual performance and reduce light levels. However, mesopic characterizes vision, whereas photopic foveal vision at all Higher scotopic / ( S/ P) ratio sources which may have a negative influence on vision. In addition, level reductions, as realized in British Standard 5489-1: 2013, impair performance. To investigate the above-described concern, we conducted two experiments. First, investigated whether Landolt...