1. Converging Lenses
Section 4.6
Lesson 13

2. Lenses
A lens is a thin transparent piece of glass or plastic that has at least one curved side
The sides can be concave, convex or both
We also use lenses for glasses!

3. Lenses A lens changes the direction in which light
If the light rays come together it is a converging lens, if the rays move apart it is a diverging lens

4. Converging lens
Because light can travel in both directions through a lens there are two focal points – one on either side of the lens

5. principal axis F1 F

6. Drawing Ray Diagrams Step 1
Draw a straight line (the axis of symmetry) through the centre of the lens perpendicular to the principal axis
An incident ray drawn parallel to the principal axis will refract through the focus on the other side of the lens

7. For an object beyond 2F1
principal axis
2F1 F F1

8. Drawing Ray Diagrams Step 2
Draw an incident ray through F1 that will refract through the lens parallel to the principal axis

9. principal axis F1 F

10. Drawing Ray Diagrams Step 3
An incident ray aimed at the centre of the lens will pass through the lens

11. principal axis F1 F

12. Identify the characteristics of this image:
principal axis F1 F
closer
inverted
smaller
real
L: _____________ O: _____________ S: ____________ T: ________

13. Notes Complete the handouts:
4.6 Converging Lenses: Drawing Ray Diagrams
4.6 What are lenses and what are some of their applications? (Summary)

14. Vocabulary Journal
Add this term and definition:
lens