1. Electromagnetic Radiation
The Nature of Light

2. The Human Eye

3. Mixing Pigments (Subtractive)
Magenta
Cyan
Yellow

4. Mixing Light (Additive)
Green
Red
Blue

5. Human Eye Sensitivity to Color
Violet Blue Green Yellow Orange Red

6. Stare at the Red Triangle

8. Stare at the Blue Triangle

10. Stare at the Green Triangle

12. Do you see a number?

13. Do you see a number? 45

14. Do you see a number? 6

15. Do You See a “2” or a “5”?

16. Color Blindness Test

17. Electromagnetic Spectrum

18. Examples Gamma rays (10-12 m) Visible light (4 x 10-7 m to 7 x 10-7 m)
violet red
Radio waves (104 m)

19. Wavelength (λ) and Frequency ()
Long Wavelength =
Low Frequency
Low Energy
Short Wavelength =
High Frequency
High Energy

20. Wavelength and Frequency are Inversely Proportional; c = 
c = 3.00 x 108 m/s (speed of light)
 = wavelength, in meters.
 = frequency in hertz (Hz or 1/s)

21. Calculate the frequency
 = 6 x 10-7m
 = 1 x 10-10m
 = 1.5 x 10-18m
 = 5.0 x 1014 Hz
 = 3.0 x 1018 Hz
 = 2.0 x 1026 Hz

22. Calculate the wavelength
 = 1 x 108 Hz
 = 1.2 x 1012 Hz
 = 3 x 1027 Hz
 = 3.0 m
 = 2.5 x 10-4 m
 = 1.0 x m

23. Energy and Frequency are Directly Proportional; E = h
E = energy in joules (J) per photon.
h = Planck’s constant = 6.63x10-34 J•s
 = frequency, in hertz (Hz or 1/s)

24. Calculate the energy  = 1 x 108 Hz 6.63 x 10-26 J  = 3.0 x 10-5 m
? ?

25. Calculating Energy per Photon
Since c = λν and E = hν, then if follows that E = hc/λ
Determine the energy per photon of an electromagnetic wave where λ= 3.0 x 10-5m
E = (6.63 x J•s)(3.0 x 108 m/s)/3.0 x 10-5m
= 6.6 x10-21 J

26. Which has the longest wavelength?
Green light or blue light?
UV light or infrared?
Green
Infrared

27. Which possesses greater energy?
Yellow light or orange light?
X-rays or radio waves?
Yellow
X-Rays