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May 25, 2024 · Luminance measures the amount of light emitted, passed through, or reflected from a particular area. It indicates how bright a surface will appear to the human eye. It is closely tied to a surface’s physical characteristics and is essential because it affects how we see and understand the world.
May 1, 2005 · < Prev Next > Light and Dark Adaptation. Michael Kalloniatis and Charles Luu. Author Information and Affiliations. Created: May 1, 2005; Last Update: July 9, 2007. Dark Adaptation. The eye operates over a large range of light levels.
- Michael Kalloniatis, Charles Luu
- 2007/07/09
- 2007
- Measurement of Illuminance
- Recommended Illuminance Levels in Rooms
- Illuminance vs. Luminance
Illuminance values can be measured with photometers. Such a device can contain a photodiode, equipped with a suitable optical filter so as to match the wavelength-dependent responsivityof the human eye. Figure 2 shows a simple multi-purpose measurement device with a built-in photodetector, which is sufficient e.g. for checking the illuminance at a ...
Illuminance values are useful in the context of the illumination of rooms. For office work and reading paper documents, it is recommended to have an illuminance around 500 lx on the desk. For comparison, full sunlight incident on a white paper generates an illuminance of the order of 100,000 lux, which can be uncomfortable. On cloudy days, the illu...
Illuminance must be strictly distinguished from the similar term luminance. These two quantities are very different, and they even have different units (lm m−2 vs. lm sr−1 m−2). Illuminance characterizes light inpinging an illuminated object, while the luminance is relevant for the visual brightnessof an object and also takes into account the angul...
The ocular motor systems control eye lid closure, the amount of light that enters the eye, the refractive properties of the eye, and eye movements. The visual system provides afferent input to ocular motor circuits that use visual stimuli to initiate and guide the motor responses.
In this chapter you will learn about how the visual system initiates the processing of external stimuli. The chapter will familiarize you with measures of visual sensation by discussing the basis of form perception, visual acuity, visual field representation, binocular fusion, and depth perception.
The retina. Light passes through the eyeball to the retina. There are two main types of light receptors - rods and cones. Rods are more sensitive to light than cones so they are useful for seeing ...
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Jan 10, 2016 · The structure and function of the eye are overviewed. This is followed by developing the basics of imaging of light with lenses, and these are used to show how sources are imaged onto the eye retina. Several optical characteristics of the eye and vision are...
