Light and Color
Early Concepts Classical Greek Ideas Newton … Particles Streamers Wave diffraction, refraction, etc
Early Concepts Einstein (1905) Photons – mass-less bundles of concentrated electromagnetic (light) energy.
Present Day Dual Nature of Light Light acts like a wave and/or a particle
Electromagnetic Waves Electromagnetic radiation is energy that is emitted by exciting electrons in atoms
Electromagnetic Waves wave – a wave that consists of oscillating electric and magnetic fields
Electromagnetic Waves
Electromagnetic Waves
Electromagnetic Waves
Electromagnetic Waves Electromagnetic spectrum- the whole range of energy waves that may be given off by electrons losing energy
Speed of Light Speed of light for all electromagnetic waves is: c = 3.0 x 108 m/s
Speed of Light Light could travel around Earth 7.5 times in one second. It takes 8 min. for light to travel from the Sun to Earth
Creating Light Illuminated body- body that reflects light waves Luminous body- body that emits light waves Illuminated body- body that reflects light waves
Colors of light Color is individual frequencies of light.
Color Wavelength Frequency Red 650 nm 462 THz Orange 600 nm 500 THz Yellow 580 nm 517 THz Green 530 nm 566 THz Blue 470 nm 638 THz Violet 400 nm 750 THz
Colors of light The primary colors of light are Red, Green and Blue
Colors of light Additive color process – Process of making colors by adding the different primary colors of light
Colors of light The secondary light colors are formed by combining the primary colors in pairs
Colors of light Red + Blue = Magenta Blue + Green = Cyan Green + Red = Yellow
Colors of light Complimentary colors- Two colors of light that, when added, produce white
Colors of light Yellow + Blue = White Cyan + Red = White Magenta + Green= White Cyan + Red = White
Pigments and Filters Pigment –material that absorbs certain colors and transmits or reflects others.
Pigments and Filters Subtractive color process – Process of making colors by subtracting different colors of light
Primary Pigment Absorbs Reflects Yellow Blue Red + Green Cyan Red Blue + Green Magenta Green Red + Blue
Secondary Pigment Absorbs Reflects Blue Red + Green Red Blue + Green Green Red + Blue
Pigments and Filters Complimentary pigments- Two pigments that, when added, produce black