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CP Physics Mr. Miller. Color Notes. General Information. Sir Isaac Newton – first to realize white light composed of different colors Prisms – separate white light into colors of light making up the visible light spectrum Each color has its own wavelength and frequency
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CP Physics Mr. Miller Color Notes
General Information • Sir Isaac Newton – first to realize white light composed of different colors • Prisms – separate white light into colors of light making up the visible light spectrum • Each color has its own wavelength and frequency • Higher frequency = greater energy • Red light – lowest frequency so least energy • Violet light – highest frequency so most energy
Seeing Colors • Color is the property of light reaching the eye • Objects absorb some colors and reflect others • We see the reflected colors!!
Color Rule #1 • The color of an opaque object depends on the frequency of light it reflects. • All colors reflected and none absorbed = white • No colors reflected and all absorbed = black
Color Rule #2 • Color of an opaque object depends on the color of light shown on it. • Red object - reflects red light • Shine white light on it – looks red • Shine red light on it – looks red • Shine green light on it – look black
Color Rule #3 • Color of a transparent object depend on the color of light it transmits. • Blue filter transmits only blue light through it. • Shine white light on it – blue passes through. • Shine blue light on it – blue passes through. • Shine red light on it – no light passes through.
Visible Spectrum • ROY G BIV – red, orange, yellow, green, blue, indigo, violet • Polychromatic = many frequencies of light colors together • Monochromatic = single frequency of light
Primary Colors of Light • Red, Blue, Green • When added together they produce white light
Secondary colors of light • Magenta, Cyan, Yellow • Produced when two primary colors added: • Red + Blue = Magenta • Blue + Green = Cyan • Green + Red = Yellow
Complementary Light Colors • A primary light color and a secondary light color that will produce white light when added together • Complements: • Red + Cyan • Green + Magenta • Blue + Yellow
Primary Pigments • Pigments = chemicals which absorb certain frequencies of light and reflect others • Primary pigments absorb one primary color of light and reflect two primary colors • Magenta – absorbs green, reflects red and blue • Cyan – absorbs red, reflects green and blue • Yellow – absorbs blue, reflects red and green • So a primary pigment absorbs its complement!
Secondary Pigments • Absorb two primary pigments and reflect one primary pigment • Red, Blue, Green
Light colors vs. Pigments • Primary colors of light = secondary pigments • Secondary colors of light = primary pigments • Mixing colors of light = ADDITIVE process • More colors added – color of light gets lighter • Mixing pigments = SUBTRACTIVE process • Pigments absorb color, so more pigments absorb more colors of light and less reflected for us to see, gets darker