1. Spectral Power Distributions “blackbody” Planckian radiators

2. Candle flame (1000K)

3. 100 W tungsten bulb (2856K)

4. Halogen 600 W bulb (3400K)

5. Sunlight (5500K)

6. Skylight (12000K)

7. Empirical fit: 2856K

8. Empirical fit: 5500K

9. Empirical fit: 2856K [400 – 700 nm]

10. Empirical fit: 5500K [400 – 700 nm]

11. h = Planck’s constant k = Boltzman constant c = speed of light λ = wavelength T = absolute temperature Planck’s Law: Empirical  Theoretical

12. Planck’s Law h = Planck’s constant k = Boltzman constant c = speed of light λ = wavelength T = absolute temperature

13. Peak wavelength

14. Wein’s Displacement Law: wavelength at peak output lambda max = b/T b = 2.898 x 10 -3 (m K) T = temperature Kelvins

15. Total power

18. 2856K 5500K 6500K

19. Stefan-Boltzman Law: total power output Total power = σ T 4 σ = Stefan-Boltzman constant T = temperature Kelvins

20. Absolute vs. relative spectral power

21. Radiometric constants: (ISO units, distance = meters) Constants: Planck's constanth6.63E-34J s speed of lightc3.00E+08m/s Boltzman's constantk1.38E-23J/K Wein's constantb2.90E-03m K Stefan-Boltzman constantσ5.670E-8W/m 2 K 4