2. Learning Objectives :To explain how we see different colors. Key Words : absorbed, reflected, transmitted, diffraction

3. How do we remember the colors of the rainbow in the correct order. Richard Of York Gained Battle In Vain

4. Why do we see white?

5. How do color filters work?

6. Filter White light Blue Light passes through Ray Box

7. Filter White light Red Light passes through Ray Box

8. Filter White light Indigo Light passes through Ray Box

9. Filter White light Green Light passes through Ray Box

10. Filter White light Green Light passes through Ray Box Filter Green light absorbed No light passes through

11. Colored filters Colored filters only let their color through. All the other colors are absorbed within the pigment that makes up the filter. Colored objects work the same way; the pigments that make up the color we see on the object filters out (absorbs the wavelengths) of the other color wavelengths in the visible spectrum.

12. 1. What color(s) will be transmitted by the red filter? redblue 2. What color will we see on the screen? Answer : red screen Answer : black 3. Why? Answer : the blue filter absorbs the red light.

13. 1. What color(s) will be transmitted by the green filter? 2. What color will we see on the screen? Answer : green Answer : black 3. Why? Answer : the blue filter absorbs the green light. greenbluescreen

14. 1. What color(s) will be transmitted by the yellow filter? 2. What color will we see on the screen? Answer : green and red Answer : red 3. Why? Answer : the red filter absorbs the green light and transmits red light. yellowredscreen

15. 1. What color(s) will be transmitted by the yellow filter? 2. What color will we see on the screen? Answer : green and red Answer : green 3. Why? Answer : the cyan filter absorbs the red light and transmits green light. yellowcyanscreen

16. If the light from the lamp is white light, made up of all colors. Why do we see it as red?

17. Only red is reflected Orange, yellow, green, blue, indigo and violet are absorbed

18. All the colors are reflected White pencil

19. All the colors are absorbed Black pencil

20. Filter White light Red Light passes through Ray Box The pencil is RED so REFLECTS the RED light We see the pencil as RED In the SAME colored light

21. Filter White light Indigo Light passes through, We see a black pencil instead of a red one Ray Box The pencil is RED so ABSORBS the indigo light. We see the pencil as BLACK because NO colors are reflected the wavelengths are all absorbed instead. In a DIFFERENT colored light

22. RedOrangeYellowGreenBlueViolet Indigo?!

23. MIXING COLORS

24. Primary Colors of Light are the blue, green, and red wavelengths

26. Can you spot something strange? Demonstration 1 (the prism) White = Red Orange Yellow green blue indigo violet Demonstration 2 (mirrors) Red Blue Green = White

27. What’s so special about red, green and blue?

28. Aqueous humor fills this space Vitreous Humor fills this space

29. Retina growing on choroid at the back of the eye

32. How does it work? Cyan is made up of and light. When you stare at the part of the image the blue and green light sensitive cells become desensitized. After this, when you look at the white screen the all the colors fall on your retina; however, only the cells are stimulated because the and cells are still inactive. Your brain only sees where the was. Now explain why yellow forms a blue after Image…

33. 1.American flag 2.Korean flag 3.A pink heart Now try and work our what colors you would need to create an after image of... 4.The yellow sun 5.Green leaf 6. Blue-green ocean, blue sky and yellow sand

52. Quick questions What are the 3 primary colors? (3 marks) What are the three secondary colors? What two primary colors is each made from? (6 marks) If you wanted to make a green after image what color would you use in the real image? (1 mark)

53. Discuss… Are there any undiscovered colors? Do we all see red the same way? Can we ever know? Could the concept of red be fully explained to a person born blind?

54. Quick REVIEW Primary colors are red, green and blue. Primary colors may be combined to make white light.

55. Primary colors of light together form white light. But primary pigments together make black. This is because they absorb all color wavelengths.

56. Transparent objects transmit color Red glass absorbs all colors of light except red, which it transmits.

57. Opaque objects reflect and absorb light This apple reflects red and absorbs all other colors.

58. Have a Good Day!