Key terms
Key terms
Theory
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
Snell’s law is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air.
Wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave’s shape repeats, and the inverse of the spatial frequency.
Refraction is the change in direction of propagation of a wave due to a change in its transmission medium.
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated.
Color is the visual perceptual property corresponding in humans to the categories called red, blue,yellow, and others.
Color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components.
Color wheel is an abstract illustrative organization of color hues around a circle that shows relationships between primary colors, secondary colors, tertiary colors etc.
RGB color model is an additive color model in which red, green, and blue light are added together in various ways to reproduce a broad array of colors.
CMY color model (process color, four color) is a subtractive color model,in which cyan, magenta yellow pigments are subtracted from each other in various ways to reproduce broad arrays of other colors.
Primary colors are sets of colors that can be combined to make a useful range of colors.
Secondary color is a color made by mixing two or more primary colors in a given color space.
Tertiary color is a color made by mixing either one primary color with one secondary color, or two secondary colors, in a given color space such as RGB and CMYK or RYB.
Monochromatic colors are all the colors (tints, tones, and shades) of a single hue.
Complementary colors are pairs of colors which, when combined, cancel each other out.
Chromatic color (psychophysical) – Psychophysical color of greater than zero purity and hence possessing a dominant or complementary wavelength. (CIE 45-25-140)
Additive color is color created by mixing a number of different light colors, with Red, green, and blue being the primary colors normally used in additive color system.
Subtractive color model explains the mixing of a limited set of dyes, inks, paint pigments or natural colorants to create a wider range of colors, each the result of partially or completely subtracting (that is, absorbing) some wavelengths of light and not others.
Colors essentials
Tints and shades a tint is the mixture of a color with white, which increases lightness, and a shade is the mixture of a color with black, which reduces lightness.
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light.
Hue is one of the main properties of a color, defined technically (in the CIECAM02 model), as “the degree to which a stimulus can be described as similar to or different from stimuli that are described as red, green, blue, and yellow,”
Lightness is a representation of variation in the perception of a color or color space‘s brightness.
Color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that of the light source.
Color rendering index (CRI) is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with an ideal or natural light source.
Illuminance is the total luminous flux incident on a surface, per unit area.
Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction.
Chromaticity is an objective specification of the quality of a color regardless of its luminance.
Colorfulness is the degree of difference between a color and gray.
Chromatic aberration is a type of distortion in which there is a failure of a lens to focus all colors to the same convergence point.
Saturation is the colorfulness of a color relative to its own brightness.
Light scattering is a form of scattering in which light is the form of propagating energy which is scattered.