1. Optics
Mirrors and Lenses

2. Law of Reflection Angle of Incidence = Angle of Reflection θi = θr
Always measured from Normal(Perpendicular) θi θr

3. Plane Mirror Flat, smooth surface from which light is reflected.
The distance the object is away from the mirror is equal to the distance the image appears to be “in” the mirror

4. Vocabulary Object distance, do Image distance, di
Distance object is from optical device
Image distance, di
Distance image is from optical device

5. Vocabulary Object Height, ho Image Height, hi Height of object
Height of image

6. Vocabulary
Real Image
Image formed by actual intersection of light rays
Image can be projected on a screen
di=(+)

7. Vocabulary Virtual Image (imaginary) Light rays do not intersect
Image can NOT be projected on screen
The eye traces back the rays to where they appeared to have once intersected
di=(-)

8. Vocabulary Upright Image Inverted Image
Object
Image
Upright Image
Image is of the same orientation as object
hi = (+)
Inverted Image
Image is inverted from the orientation of the object
hi = (-)
Object
Image

9. Vocabulary Magnification, M
Ratio of the image height to the object height
M=(+) image is upright
M=(-) image is inverted

10. Plane Mirror
Mirror
do = -di
ho=hi
M=1

12. Spherical Mirrors Concave Mirrors Convex Mirrors
Mirror surface is on the inside of the curve
Convex Mirrors
Mirror surface is on the outside of the curve

13. Focal Point
Point where light converges
Half the radius f C

14. Concave Mirror
Ray that is initially parallel to central axis reflects through focal point
Ray that is initially through focal point reflects parallel to central axis
Ray that is incident at vertex, reflects at same angle
Ray that travels through center of curvature will reflect back through center of curvature

15. Concave Mirror f C

16. Mirror Equation

17. Example f C
do = 30 cm
f = 10 cm
di = ?
di = 15 cm
M = -0.5

18. Convex Mirror
Ray that is initially parallel to central axis reflects through virtual focal point
Ray that is initially through virtual focal point reflects parallel to central axis
Ray that is incident at vertex, reflects at same angle
Ray that travels through center of curvature will reflect back through center of curvature

19. Example f C

20. Example
di = ?
f = -10 cm
do =15 cm
di = -6 cm
M = 0.4

22. Lenses Converging Lenses Diverging Lenses Biconvex f=(+) Biconcave

23. Converging Lens Rays
Ray that is initially parallel to central axis will refract through far focal point
Ray that is initially through near focal point will refract parallel to central axis
Ray that passes through center of lens pass without refraction

24. Converging Lens

25. Converging Lens Example
f = 10 cm
di= ?
do = 20 cm
di= 20 cm
M = 1

26. Diverging Lens Rays
Ray that is initially parallel will refract as if coming from near focal point
Ray that is initially through far focal point will refract as if coming from parallel
Ray that passes through center will continue on

27. Diverging Lens

28. Diverging Lens Example
do = 25 cm
f = -10 cm
di = ?
di = cm
M = 0.3

29. Lenses in Combination
Image from the first lens becomes the object for the second lens

30. Lenses in Combination

31. Lenses in Combination do1 = 25 cm f2 = 8 cm di2 = 12 cm f1 = 10 cm