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A surface that reflects sunlight . . . without absorbing any of its colors is said to be white.

A surface that reflects sunlight . . . without absorbing any of its colors is said to be white. A surface that absorbs all colors, reflecting none, is said to be black. Weak vibrations of white light result in the ...
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About terms

A family of closely related terms underpins all the content at lightcolourvision.org and we aim for accuracy and consistency of usage as we demonstrate the connections between light, colour and vision. We want our resources to be accessible to a ...
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Absorption

When light strikes an opaque material the wavelengths that are not reflected are absorbed and their energy is converted to heat. When sunlight strikes an opaque object or material, it can be reflected or absorbed. If the light is reflected ...
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Accommodation

Accommodation refers to the way the eye increases optical power by changing the shape of the lens. This is necessary to produce a clear, focused, image of an object when it is near to the eye. The eye focuses on a given object ...
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Achromatic

Any colour that lacks strong chromatic content is said to be achromatic, unsaturated, or near neutral. Pure achromatic colours include black, white and all greys. Achromatic, unsaturated colours include browns, tans, pastels and darker colours. Achromatic, unsaturated colours can be ...
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Additive colour

Additive colour involves mixing different wavelengths of light to produce other colours. Whilst additive colour is the method used to mix wavelengths of light, subtractive colour is the method used to mix dyes, inks and paints. An additive approach to ...
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Additive colour

Additive colour is a method of mixing different wavelengths of light to produce other colours. An additive approach to colour is used in the case of emission of light from the screens of mobile phones, computers and televisions. An additive ...
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Adobe RGB colour space

The Adobe RGB (1998) colour space is an RGB colour space developed by Adobe Systems, Inc. The Adobe RGB (1998) colour space was designed to encompass most of the colours that can be output by CMYK colour printers. When using ...
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AI (Adobe Illustrator) file format

Download the image at the top of this page as an AI (Adobe Illustrator) file: All AI images available for download from lightcolourvision.org are 1686px wide. All the images on these Resource Pages were created in Adobe Illustrator and are ...
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Amacrine cell

Amacrine cells are interneurons in the human retina that interact with retinal ganglion cells and/or bipolar cells. Amacrine cells interact with bipolar cells and/or ganglion cells. They are another type of interneuron which in this case monitor and augment the ...
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Amplitude

The amplitude of a wave is a measurement of the distance from the top of a crest through the centre line  (the still position, zero-point, mid-point) to the bottom of a trough. In the case of an electromagnetic wave, amplitude ...
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Amplitude

The amplitude of a wave is a measurement of the distance from the top of a crest through the centre line  (the still position, zero-point, mid-point) to the bottom of a trough. In the case of an electromagnetic wave, amplitude ...
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Analogous colours

Analogous colours are groups of colours that are adjacent to each other on a colour wheel, with one being the dominant colour. The dominant colour amongst a group of analogous colours is usually a primary or secondary colour. The immediately adjacent colours to secondary ...
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Angle of incidence

The angle of incidence measures the angle at which incoming light strikes a surface. The angle of incidence is measured between a ray of incoming light and an imaginary line called the normal. In optics, the normal is a line drawn ...
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Angle of incidence

The angle of incidence measures the angle at which incoming light strikes a surface. The angle of incidence is measured between a ray of incoming light and an imaginary line called the normal. In optics, the normal is a line drawn ...
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Angle of reflection

The angle of reflection measures the angle at which reflected light bounces off a surface. The angle of reflection is measured between a ray of light which has been reflected off a surface and an imaginary line called the normal ...
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Angle of reflection

The angle of reflection measures the angle at which reflected light bounces off a surface. The angle of reflection is measured between a ray of light which has been reflected off a surface and an imaginary line called the normal ...
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Angle of refraction

The angle of refraction measures the angle to which light bends as it passes across the boundary between different media. The angle of refraction is measured between a ray of light and an imaginary line called the normal. In optics, ...
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Angle of refraction

The angle of refraction measures the angle to which light bends as it passes across the boundary between different media. The angle of refraction is measured between a ray of light and an imaginary line called the normal. In optics, ...
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Atom

An atom is the smallest particle that can be described as a chemical. At the centre of an atom is a nucleus containing protons which are positively charged sub-atomic particles. The number of protons determines what chemical the atom is ...
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