The authors test 168 luminance-calibrated high dynamic range photographs with associated subjective user data against a set of plausible visual comfort metrics and identify metric thresholds at which discomfort can be consistently identified with minimal false-positives. Correlations were identified with vertical eye illuminance, DGI, DGP 5 ∗ Ltask, max. window luminance and max. workplane lumi...

The precision of depth discrimination has been measured in a two-rod test apparatus involving real-depth cues. The effects of two variables have been studied: (a) the level of equal retinal illuminance presented to the two eyes; and (b) the difference in the level of the retinal illuminance presented to the two eyes. It has been found that depth discrimination in this test varies as a function ...

This study aims to examine the search efficiency under low illuminance conditions for three safety colors; red, orange and yellow, which are used for danger and caution signs. They are subjected to a visual search task. Images of visual stimuli consisting of an array of colored circles placed on a large visual field (a visual angle of 40 deg.) were displayed on an 80-inch screen through a proje...

Venetian blinds play an important role in controlling daylight in buildings. Automated blinds overcome some limitations of manual blinds; however, the existing automated systems mainly control the direct solar radiation and glare and cannot be used for controlling innovative blind systems such as split blinds. This research developed an Illuminance-based Slat Angle Selection (ISAS) model that p...

BACKGROUND Melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) play an important role in non-image forming responses to light, such as circadian photoentrainment, light-induced melatonin suppression, and pupillary light response. Although it is known that there are some single nucleotide polymorphisms (SNPs) in the melanopsin (OPN4) gene in humans, the association...

We are doing reseaching and development of an intelligent lighting system to provide desired brightness to a desired place. In this study, we consider how to satisfy target illuminance for each worker and minimize power consumption with not only luminous intensity for each light but also the height of luminaire as the design variables. Therefore, highly-accurate target illuminance as well as ve...

The illuminance responsivities of two transfer standard photometers have been directly determined from their spectral responsivity calibrations at two different calibration facilities of NIST. The main characteristics of the two photometers, and their calibrations are described. The spectral and broad-band (illuminance) responsivities measured at the two different facilities are compared. The t...

The range of calibration of illuminance meters and luminance meters has been normally limited to levels up to several thousand lx and several thousand cd/m2 using a high-power luminous intensity standard lamp. The calibration of instruments at much higher levels is required in applications such as daylight measurement, evaluation of solar simulators, and testing light sources in imaging devices...