1. Images Formed by Lenses
(Page 199)

2. Images formed by Lenses
Using ray diagrams, you can predict the location, orientation, size and type of image as it appears through a lens
Once the focal point has been identified, 3 key rays close to the principal axis are chosen to locate the image
Lens ray diagrams are simplified in two ways: (1) partial reflection/refraction is ignored; (2) refraction that should occur is replaced with only one bend at the axis of symmetry (shown by a vertical line through the lens)

3. Ray Diagrams for Converging & Diverging Lenses

4. Ray Diagrams for Converging & Diverging Lenses

5. Ray Diagrams for Converging Lenses

6. Ray Diagrams for Converging Lenses

7. A General Ray Diagram for a Converging Lens

8. Image Characteristics of Converging Lenses
Some images formed by converging lenses are inverted; while others are upright
To determine the orientation of the image, draw ray diagrams with the object in different positions relative to the lens
3 cases for converging lenses: Object between focal point and lens; object between one and two focal lengths and object beyond two focal lengths

9. Image Characteristics of Converging Lenses

10. Case 1: Object between Focal Point and lens
Farther, upright, larger & virtual

11. Case 2: Object between 1 and 2 F
Farther, inverted, larger & real

12. Case 1: Object beyond 2F F F 2F 2F
Closer, inverted, smaller & real

13. Ray Diagrams for Converging & Diverging Lenses

14. Ray Diagrams for Diverging Lenses

15. Ray Diagrams for Diverging Lenses

16. Ray Diagrams for Diverging Lenses
Closer, upright, smaller & virtual

17. Image Characteristics of Diverging Lenses
For diverging lenses, the image is always upright, virtual. Closer to the lens and smaller
As the object moves farther from the lens, the image gets smaller

18. H.W…All questions on page 561

19. Thin Lens and Magnification Equations (converging lenses only!)
Remember that:
f is the focal length
do is the distance from the lens to the object
di is the distance from the lens to the image
ho is the height of the object
hi is the height of the image
Do questions # on page