Search results
Results From The WOW.Com Content Network
Scotopic vision is produced exclusively through rod cells, which are most sensitive to wavelengths of around 498 nm (blue-green) [3] and are insensitive to wavelengths longer than about 640 nm. [4] Under scotopic conditions, light incident on the retina is not encoded in terms of the spectral power distribution .
Above a certain luminance level (about 0.03 cd/m 2), the cone mechanism is involved in mediating vision; photopic vision. Below this level, the rod mechanism comes into play providing scotopic (night) vision. The range where two mechanisms are working together is called the mesopic range, as there is not an abrupt transition between the two ...
The standard scotopic luminous efficiency function or V ′ (λ) was adopted by the CIE in 1951, based on measurements by Wald (1945) and by Crawford (1949). [15] Luminosity for mesopic vision, a wide transitioning band between scotopic and phototic vision, is more poorly standardized. The consensus is that this luminous efficiency can be ...
The visible range of light is defined by what is readily perceptible to humans, thought the visual perception of non-humans often extends beyond the visual spectrum. The resulting perception is also known as vision, sight, or eyesight (adjectives visual, optical, and ocular, respectively).
The range is defined psychometrically by the luminous efficiency function, which accounts for all of these factors. In humans, there is a separate function for each of two visual systems, one for photopic vision, used in daylight, which is mediated by cone cells, and one for scotopic vision, used in dim light, which is mediated by rod cells ...
An animated sequence of simulated appearances of a red flower (of a zonal geranium) and background foliage under photopic, mesopic, and scotopic conditions. The Purkinje effect or Purkinje phenomenon (Czech: [ˈpurkɪɲɛ] ⓘ; sometimes called the Purkinje shift, often pronounced / p ər ˈ k ɪ n dʒ i /) [1] is the tendency for the peak luminance sensitivity of the eye to shift toward the ...
Mesopic vision, sometimes also called twilight vision, is a combination of photopic and scotopic vision under low-light (but not necessarily dark) conditions. [1] Mesopic levels range approximately from 0.01 to 3.0 cd/m 2 in luminance. Most nighttime outdoor and street lighting conditions are in the mesopic range. [2]
Photopic vision is characteristic of the eye's response at luminance levels over three candela per square metre. Scotopic vision occurs below 2 × 10 −5 cd/m 2. Mesopic vision occurs between these limits and is not well characterised for spectral response. [2] [1]