1. DO NOW Sit where your seat normally would be in the room
Open notebooks to a new page for chapter 4

2. LENSES

4. Optics: the study of visible light and the ways in which visible light interacts with the eye to produce vision mirrors, lenses  optical tools telescopes, microscopes  combine optical tools

5. Recall…
Refraction is the bending of light when it moves from one matter to another

6. Reflection is the bouncing of light off an object
Recall…
REFLECTION
Reflection is the bouncing of light off an object

7. REFLECTION Law of Reflection
According to the law of reflection, the angle of incidence is equal to the angle of reflection.
“Incidence” refers to the wave that comes in contact with a surface.

8. LAW OF REFLECTION

9. Types of Reflection
Regular reflection: light rays that come from the same direction will bounce off in the same new direction.
--occurs with smooth surfaces (mirror)
Diffuse Reflection: light rays that come from the same direction will bounce off in many new directions.
--occurs with not very smooth surfaces

10. Shape determines how mirrors form images
Image: Picture of an object formed by waves of light
Flat Mirrors – image looks exactly the same as the object
Convex – curved
outward
inward

11. Convex vs Concave Mirrors

12. Refraction occurs in both concave and convex lenses.
A lens is a piece of material in which light is able to pass through and is used to refract light.

13. Lenses and Images
A lens forms an image by REFRACTING light rays that pass through it.
The type of image formed by a lens depends on the shape of the lens and the position of the object.

14. There are 2 types of lenses:
TWO TYPES OF LENSES
There are 2 types of lenses:
CONVEX
CONCAVE

15. Concave Lens
A concave lens is thinner in the middle than at the edges and causes light rays to spread apart (divergence)
It looks like there is a cave on both sides!! So, it must be concave!!

16. Convex Lens
A convex lens or magnifying glass is thicker in the middle then on the ends which causes the light rays focus (converge)

17. CONCAVE AND CONVEX LENSES
Concave lenses make light rays move away from each other or spread out
A convex lens can focus the light that enters it and direct it to one point.

18. Convex Lenses and Images
Depending on where you hold the lens--the image you see will either be right side up (real image) or upside down(virtual image)

19. Concave Lenses and Images
A concave lens produce upright images that are smaller than the real object.

20. Examples of CONVEX lenses
Magnifying glass
Cameras
Telescopes
Our Eyes
Glasses

21. Example of CONCAVE lenses
Nearsighted eyeglasses
(can’t see far away)

22. Bill Nye Video

23. LENSES AND VISION NEARSIGHTED- Difficulty in seeing objects far away
FARSIGHTED- Difficulty is seeing objects up close
Concave Lens
Convex Lens

24. Water Lens Experiment
Make Hypothesis

25. Which lens converges light? Which lens diverges light?

26. Which is concave and which is convex?