Light
Light that is visible to humans (visual) is electromagnetic radiation with wavelengths between around 380 and 760 nm.
Below 400 nm, we speak of ultraviolet radiation (UV), which is extremely hard UV radiation down to 10 nm. The UV ranges of radiation, which also include sunlight, are referred to as UV-B from 280 – 315 nm and UV-A from 315 – 400 nm. The UV-C range extends from 100 – 280 nm.
Above the visible range, this is referred to as infrared radiation (IR). It covers the wavelength ranges from 780 – 2500 mm in the near IR (NIR) and the ranges from 2.5 – 50 µm in the mid IR.
Fig.: Spectrum of electromagnetic radiation with the range of the spectrum of light visible to humans.
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The properties of light can be described with wave-characteristic as well as particle-characteristic properties. A large number of phenomena and effects occur in industrial image processing that can be derived directly from this. The light emission of LED lighting can also be explained by these quantum mechanical aspects.
The following effects can occur when light interacts with (test) objects
– Absorption of certain wavelengths (colors)
– Emission of certain wavelengths (e.g. B. Fluorescence)
– Reflection of incident light
– Generation of interference patterns(mostly disruptive)
– Refraction at surfaces (interfaces)
– Polarization effects
