Presentation on theme: "Light & Color. Light: Light that can be sensed by our eyes is Visible Light Visible light consists of a continuous range of wavelengths or frequencies."— Presentation transcript:
Light & Color
Light: Light that can be sensed by our eyes is Visible Light Visible light consists of a continuous range of wavelengths or frequencies Specific wavelengths correspond to a specific color based upon how we perceive light of that wavelength
Dispersion & Recomposition: If a prism is placed in a beam of white light:
Dispersion occurs resulting in the separation of light into a spectrum of colors A type of refraction Refractive index varies with the wavelength or color of light Lower the wavelength, higher the refractive index Dispersion due to different refractive angles How rainbows occur
Recomposition recombines the colors of the spectrum
When light strikes an object, the specific wavelengths can be absorbed or reflected The wavelengths that are reflected by an object, cause the perceived color of the object Ex. ROYGBIV Capable of absorbing ROYBIV G ROYBIV all absorbed by object G reflected Therefore object appears green
If all absorbed, then object appears black If all reflected, then object appears white
What color will the objects appear to be? ROYGBIV Capable of absorbing ROY Capable of absorbing YGBIV Capable of absorbing ROYGBIV RORO GBIVGBIV nothing BLACK
Viewing objects: Objects may be viewed through filters &/or under different light Causing the color of objects to be perceived differently Recall white light is ROYGBIV
Filters will only allow specific colors of light (& the color on either side in the spectrum) to pass Ex. ROYGBVROYGBV Blue Filter GBVGBV
ROYGBVROYGBV Yellow Filter OYGOYG White light passes through a yellow filter. What color light will pass?
Recall colors are perceived b/c of the color of light reflected Viewing objects under different color light will affect the perceived color since some colors may or may not be present to be reflected!!!
ROYGBVROYGBV Blue Filter GBVGBV A white dress is viewed under a blue filter. What color will the dress appear? BLUE
ROYGBVROYGBV Green Filter YGBYGB A yellow shirt is viewed under a green filter. What color will the shirt appear? Yellow
ROYGBVROYGBV Yellow Filter OYGOYG A red shirt is viewed under a yellow filter. What color will the shirt appear? BLACK
ROYGBVROYGBV A blue shirt is viewed under red light. What color will it appear? BLACK
ROYGBVROYGBV A blue shirt is viewed under green light. What color will it appear? BLUE
Standing on a stage, a singer is illuminated by three lights, each emitting a different color. When the first light is used, he appears to be wearing black shoes, red pants & a red shirt When the second light is used, he appears to be wearing blue shoes, black pants & a blue shirt When the third light is used, he appears to be wearing black shoes, black pants & a green shirt What color are the singers shoes, pants & shirt?
ShoesPantsShirt 1 st LightBlkRed 2 nd LightBlueBlkBlue 3 rd LightBlk Green GBVGBV Reflecting blue so…. Shoes are blue RORO Reflecting all so… Pants are red RORO GBVGBV YGBYGB Reflecting red so… Shirt is white Red Blue Green
Color Addition: White light is ROYGBIV but… White light can also be produced by adding colors (or frequencies) Any three colors of light which produce white light when combined are primary colors of light RED, GREEN & BLUE
By adding primary colors of light, other colors can be produced Ex. TVs, computers, stage lights RedGreen Blue Yellow CyanMagenta White
Any two colors of light which when mixed together in equal intensities produce white are complementary colors of eachother Ex. Red & Cyan Blue & Yellow Green & Magenta
If magenta light and yellow light are added together, will white light be produced? Magenta = Red & Blue Yellow = Red & Green Light will appear light pink
Color Subtraction: Process of removing color Increasing absorption of colors and decreasing reflection of colors Ex. Paint pigments, printer ink Pigment capable of absorbing blue light R G BR G BR GR G Blue absorbed Red & Green Reflected Therefore object appears yellow
Pigment capable of absorbing green light R G B R B R B Green absorbed Red & Blue Reflected Therefore object appears magenta What color would an object capable of absorbing green light appear?
Primary colors (pigments) of paint are cyan, magenta & yellow Each primary color of paint absorbs one primary color of light Cyan Yellow Magenta Blue Red Green Cyan absorbs Red Magenta absorbs Green Yellow absorbs Blue