Goniophotometer
A device that measures the light distribution characteristics of a source by capturing luminous intensity at various angles.
Mesopic Vision
Vision in intermediate lighting conditions, involving both rod and cone cells, affecting color and detail perception.
Scotopic Vision
Vision under low-light conditions, primarily mediated by rod cells, resulting in monochromatic perception.
Photopic Vision
Vision under well-lit conditions, primarily mediated by cone cells, enabling color perception.
Cone Cells
Cone cells are the other type of image-forming photoreceptor cells found in the retina of the eye. They function primarily in bright light conditions and are responsible for detecting color. Unlike rod cells, cone cells enable the perception of fine detail and contribute to central vision. There are three types of cone cells, each sensitive…
Rod Cells
Rod cells are one of the two types of image-forming photoreceptor cells found in the retina of the eye. They are responsible for vision in low light conditions and are highly sensitive to light, but they do not detect color. Rod cells provide the ability to see in dim lighting and contribute to peripheral vision.
SPD (Spectral Power Distribution) Graph
A visual representation of the intensity of light across different wavelengths. SPD graphs characterize light sources’ color quality and biological effects, offering insights into circadian compatibility.
Spectrometer
A spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically by separating the light into its component wavelengths and measuring the intensity of each wavelength. This information is crucial for analyzing the spectral power distribution (SPD) of light sources, among other applications such as…
Spectral Power Distribution
The spectral power distribution (SPD) of a measured light source refers to the range and intensity of wavelengths emitted by the source within the visible light spectrum, typically from approximately 380 nanometers to 780 nanometers. The SPD characterizes how much power the light emits at each wavelength, influencing the perceived color and quality of the…
Tabletop lux
The illuminance measured on a horizontal work surface, expressed in lumens per square meter. This metric is crucial for evaluating workspace lighting quality and compliance with standards like WELL.