1 / 31

Chapter 27 Color

Chapter 27 Color. Spectrum of Visible Light. Red Photon. Wavelengths & Photons. Particles of light, called photons, each have a wavelength. Yellow Photon. Green Photon. Blue Photon. Prism Spectrum. Newton’s Color Wheel.

midori
Download Presentation

Chapter 27 Color

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 27Color Physics 1 (Garcia) SJSU

  2. Spectrum of Visible Light Physics 1 (Garcia) SJSU

  3. Red Photon Wavelengths & Photons Particles of light, called photons, each have a wavelength. Yellow Photon Green Photon Blue Photon Prism Spectrum Physics 1 (Garcia) SJSU

  4. Newton’s Color Wheel Prism spectrum is a straight line, so why did Isaac Newton describe color using a circular wheel? Physics 1 (Garcia) SJSU

  5. Not in the spectrum. How do we see these? Spectral Colors Additive Color Wheel R M Y Red Yellow Green Cyan Blue Magenta G B C Physics 1 (Garcia) SJSU

  6. Adding Colored Lights Stream of red & green photons looks same as yellow photons (metamerism) YELLOW Eye to Brain or Notice overlap of red, green, & blue is seen as white light Theatrical lighting Physics 1 (Garcia) SJSU

  7. Demo: Seeing Yellow Sodium lamps emit yellow photons Color monitor can only emit red, green, and blue (RGB); creates other colors by selectively turning RGB pixels on or off. Physics 1 (Garcia) SJSU

  8. Trichromatic Theorists James Clerk Maxwell (1831-1879) Scottish physicist Thomas Young (1773-1829) English physicist • Hermann von Helmholtz • (1821-1894) • German physicist Physics 1 (Garcia) SJSU

  9. Simple Trichromatic Theory Yellow & Red photons excite me Yellow, Green & Cyan photons excite me Cyan & Blue photons excite me MOE LARRY CURLY Inside your eye there are three receptors Physics 1 (Garcia) SJSU

  10. Trichromatic: Seeing Yellow Yellow & Red photons excite me. I’M EXCITED Yellow, Green & Cyan photons excite me. I’M EXCITED Cyan & Blue photons excite me. Yawn. CURLY MOE LARRY Yellow seen when Curly and Larry excited, either by yellow photons or red & green photons. Physics 1 (Garcia) SJSU

  11. Trichromatic: Seeing Magenta Yellow & Red photons excite me. I’M EXCITED Cyan & Blue photons excite me. I’M EXCITED Yellow, Green & Cyan photons excite me. Yawn. CURLY MOE LARRY Magenta is seen by eye when Moe and Larry excited, which no single type of photon can achieve. Physics 1 (Garcia) SJSU

  12. Demo: Maxwell Color Disk Disk painted half red, half blue looks magenta when rapidly spinning. Physics 1 (Garcia) SJSU

  13. Mixing Blue & Red Paint Mixing paint or ink is different from adding colors together by light. Mix of blue and red paint produces a blackish brown Physics 1 (Garcia) SJSU

  14. Trichromatic: Seeing White Yellow & Red photons excite me. I’M EXCITED Cyan & Blue photons excite me. I’M EXCITED Yellow, Green & Cyan photons excite me. I’M EXCITED CURLY MOE LARRY White seen when all three very excited Gray seen when all three less excited Physics 1 (Garcia) SJSU

  15. Trichromatic: Color Blindness Red , Yellow, Green & Cyan photons excite me. I’M EXCITED Cyan & Blue photons excite me. Yawn. Color blindness occurs if the eye is missing one of the three receptors. Other receptors try to compensate but cannot distinguish some colors. CURLY MOE LARRY Do I see red or green? Physics 1 (Garcia) SJSU

  16. Color Blindness Weakness or absence of one of the three types of cones is the cause of color blindness, leading to a reduced ability to distinguish colors. 29 or 70? 21 or 74? Physics 1 (Garcia) SJSU

  17. I’M EXCITED! Yawn. Yawn. Then stare at WHITE MOE LARRY CURLY Me too, but tired. I’M EXCITED! ME TOO! First stare at RED MOE LARRY CURLY Trichromatic: After-Image Moe and Curly are excited so what color is seen? CYAN (light blue-green) Physics 1 (Garcia) SJSU

  18. Negative After-image Stare, unfocused, at the red cross for 10 seconds then look at white wall Physics 1 (Garcia) SJSU

  19. Negative After-image Cyan Physics 1 (Garcia) SJSU

  20. Negative After-image Physics 1 (Garcia) SJSU

  21. Negative After-image Yellow Cyan Magenta Physics 1 (Garcia) SJSU

  22. Simple Additive Color Wheel LARRY Newton’s color wheel is a simple formulation of trichromatic theory. White CURLY MOE Physics 1 (Garcia) SJSU

  23. Color Vision in the Eye Three types of cones (color) One type of rod (B/W only) Physics 1 (Garcia) SJSU

  24. CIE Hue-Saturation Diagram Eye is not a perfect optical instrument. Color “wheel” is actually distorted cone shape. Rim is full saturation, center is white CURLY % 50% Larry 50% Curly 0% Moe 33% Larry 33% Curly 33% Moe LARRY % Physics 1 (Garcia) SJSU

  25. Spectral Reflectance Curves White Red When white light shines on an object, some photons absorbed, others reflected by the object’s surface. Physics 1 (Garcia) SJSU

  26. BLUE GREENRED 100% 0% Name That Color BLUE GREENRED BLUE GREENRED Dark Brown (Burnt Sienna) White Red Physics 1 (Garcia) SJSU

  27. BLUE GREENRED 100% 0% Name That Color BLUE GREENRED BLUE GREENRED Bluish Green Bright Yellow Blue (Cobalt) Physics 1 (Garcia) SJSU

  28. Subtractive Color Absorbing filters or absorbing pigments remove colors from white light. Check Yourself: Yellow = Red + Green Cyan = Blue + Green Yellow & Cyan filters (or pigments) combine to give … Overlapping color filters Physics 1 (Garcia) SJSU

  29. Check Yourself A soap film absorbs red, green, or blue light, depending on the film’s thickness. What colors do we see where red is removed? Where green is removed? Where blue is removed? Physics 1 (Garcia) SJSU

  30. Four Color Printing Black Cyan Magenta Yellow Green balloon printed with mix of yellow and cyan inks Magenta + Yellow + Cyan All Four Physics 1 (Garcia) SJSU

  31. Black Cyan Magenta Yellow Check Yourself Which inks are mixed for the bright red balloon and dark red dress? Physics 1 (Garcia) SJSU

More Related