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Technical environment

Technical environment

Global standard 220V-240V/50Hz-60Hz
Standard for USA/Canada 120V/60Hz, 277V/60Hz
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Our contents are shown to you in English. Product data is displayed for a technical region using 220V-240V/50Hz-60Hz.

Mesopic vision (twilight vision): Definition

Mesopic vision: Representation of the sky at twilight.

Mesopic vision is the transitional state from seeing by day (photopic vision) using the cones, to seeing by night (scotopic vision) using the rods. This is why it is also called twilight vision. Upon decreasing brightness, our colour perception and visual acuity deteriorate until we finally only recognise differences in brightness.

Good to know:

Experts speak of mesopic vision between luminances of 3 cd/m2 and 0.01 cd/m2.

ERCO Light Knowledge is also available as a whitepaper:

Further topics on seeing and perceiving

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