Photometry · 2 min read
Basic definitions related to light
Photometry describes optical radiation while accounting for the spectral sensitivity of human vision. Learn the quantities used to organise light measurements.
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Light measurement knowledge
Definitions, methods and practical contexts explained in clear engineering language.
Photometry · 2 min read
What is luminance?
Luminance describes the brightness of a surface in a specific viewing direction. It is central to evaluating displays, luminaires and road lighting.
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What is spectral distribution?
A spectral distribution shows how radiant energy is distributed with wavelength. It is an optical fingerprint of a light source.
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What is illuminance?
Illuminance describes luminous flux incident on a unit area. It is a fundamental quantity for workplaces, interiors and outdoor areas.
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What is luminous intensity?
Luminous intensity describes the directional properties of a source and shows how a luminaire distributes flux in space.
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How a spectrometer works
A spectrometer converts complex optical radiation into an ordered record of intensity versus wavelength.
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Point and imaging luminance measurement
Choosing between a spot meter and a camera depends on object geometry, required spatial resolution and the analysis objective.
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What is a photometric solid?
A photometric solid is a spatial representation of the luminous intensity of a source or luminaire in the considered directions.
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