Dictionary of light, colour & vision

A rainbow is an optical effect, a trick of the light, caused by the behaviour of light waves travelling through transparent water droplets towards an observer. Sunlight and raindrops are ...

This DICTIONARY OF LIGHT, COLOUR & VISION contains a vocabulary of closely interrelated terms that underpin all the resources you will find here at lightcolourvision.org. Each term has its own ...

When light strikes an object, some wavelengths are absorbed and their energy is converted to heat, others undergo reflection or transmission. When light is absorbed by an object or medium, ...

Accommodation refers to the way the lenses inside our eyes accommodate for the fact that objects of interest may be close to or at a distance. Sharp images on the ...

Accommodation The distance between the retina (the detector) and the cornea (the refractor) is fixed in the human eyeball. The eye must be able to alter the focal length of ...

Achromatic means without colour so refers to surfaces or objects that appear white, grey or black. Achromatic colors lack hue or saturation but can be described in terms of their ...

About additive and subtractive colour models There are two main types of colour models, additive and subtractive. Additive Colour Models Additive colour models are used when blending light to produce ...

Additive colour mixing combines wavelengths of light to produce the vast array of hues an observer sees on TV, computer and phone screens. Colour models that use an additive approach ...

About additive colour & the RGB colour model The RGB colour model used by TV, computer and phone screens involves additive colour mixing. The RGB colour model produces all the ...

An additive colour model explains how different coloured lights (such as LEDs or beams of light) are mixed to produce other colours. The RGB colour model and HSB colour model ...

The Adobe RGB (1998) colour space was developed by Adobe Systems. It aims to ensure the optimal range of colours available within the RGB colour model are accurately reproduced when ...

About Adobe RGB, ProPhoto RGB & sRGB The most common colour profiles in photography are sRGB, Adobe RGB (1998), and ProPhoto RGB. Adobe RGB, developed in 1998, consists of the ...

Alexander's band (Alexander's dark band) is an optical effect associated with rainbows. The term refers to the area between primary and secondary bows that often appears to be noticeably darker ...

Alexander's band, also known as Alexander's dark band, is an optical phenomenon observed in rainbows. It refers to the region between the primary and secondary bows, which often appears noticeably ...

About amacrine cell functions Amacrine cells are a type of neuron found in the retina, the light-sensitive tissue lining the back of the human eye. They play a critical role ...

Amacrine cells are interneurons in the human retina that interact with retinal ganglion cells and/or bipolar cells. Amacrine cells are a type of interneuron within the human retina. Amacrine cells ...

Amacrine cells Amacrine cells interact with bipolar cells and/or ganglion cells. They are a type of interneuron that monitor and augment the stream of data through bipolar cells and also ...

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 ...

The amplitude of an electromagnetic wave is directly connected with the amount of energy it carries. In a wave diagram, amplitude is represented as the distance from the center line ...

About amplitude, brightness, colour brightness and intensity The terms amplitude, brightness, colour brightness and intensity are easily confused. In this resource: Amplitude Amplitude refers to the amount of energy carried ...