This presentation contains the definition of refraction and how to describe the image formed by lenses using the ray diagram technique.

1. Prepared by: Ms. Hanna Mae G. Hernani

2. ➢ the change in the
direction of light when
it passes from one
medium to another

3. Important terms:
Air
Water
boundary
θi
θr
Incident ray
Refracted ray
Normal

6. SPECULAR OR DIFFUSE?

7. 1a. The ray of light moves closer to the normal
when it travels from less dense to denser medium.
1b. The ray of light moves away from the normal
when it travels from denser to less dense medium.

8. 2. An incident ray passing through the
normal always goes straight.

10. a piece of glass or transpa-
rent material having at least
one spherical surface

15. F’
2F’ F 2F
Optical axis
Primary focus
Center of curvature
Optical Center
(geometric center)
Secondary focus
Secondary center of curvature

16. F’
F
2F 2F’
Primary focus
Secondary focus

17. Type of Lens
Location of
image
(back or front)
Orientation
(upright, inverted)
Convex
lens
back or front
Inverted or
upright
Concave
lens
back upright

18. Type of
Lens
Size of image
(same, reduced,
enlarged)
Type
(real or virtual)
Convex
lens
same size, reduced,
or enlarged
real or virtual
Concave
lens
smaller virtual

20. Lesson Target:
❑ To describe the
characteristics of image
formed by convex and
concave lenses

21. Special Light Rays
1

22. 1

23. 2

24. 2

25. 3

26. 3

27. L
O
S
T
1 - Beyond 2F’ (C)

28. L
O
S
T
2 - at 2F’ (C)

29. L
O
S
T
3 - bet 2F’ and F’

30. L
O
S
T
4 – at F’

31. L
O
S
T
5 – bet F’ & Optical center (O)

32. Object
Location
Characteristics of Image Formed
L O S T
Beyond 2F’ Front Inverted Smaller Real
At 2F’ Front Inverted Same size Real
Bet. 2F’ & F’ Front Inverted Larger Real
Bet. F’ and O Back Upright Larger Virtual
At F’ No Image is Formed

33. F
2F 2F’
F’
back front
L
O
S
T

34. F
2F 2F’
F’
L
O
S
T

35. F
2F 2F’
F’
L
O
S
T

36. F
2F 2F’
F’
L
O
S
T