1. Review from last class – Complete in your notes. 1.A pinhole camera creates an image of a 37- meter-tall tree. If the image is 2.4 cm tall and inverted, what is the magnification of the camera? 2.Mirrors divert light using ______________, lenses divert light using ______________. 3.Describe the difference between specular and diffuse reflection.

2. Assignment 3/23 and3/24 Turn in optical devices worksheet Homework: Read 20.3 and 20.4 Page 596, 1-13, 29, 30, 31, 52, 55,

3. Ray Diagrams (3/25 and 3/26) Mirrors

4. Reflection Reflection from a mirror: Incident ray Normal Reflected ray Angle of incidence Angle of reflection Mirror

5. The Law of Reflection Angle of incidence = Angle of reflection In other words, light gets reflected from a surface at THE SAME ANGLE it hits it. The same !!!

6. Flat Mirrors Angle of incidence Angle of reflection = Normal

7. Flat Mirrors If the rays leave the optical system and appear to come from some point in space, the point they appear to come from is a virtual image. The converging reflected rays indicate the location of the image

8. Image Descriptions How can we describe this image? 1.Is it upright or inverted? 2.Is it magnified or unmagnified? 3.Is it virtual or real?

9. Image Description This is an UPRIGHT, UNMAGNIFIED AND VIRTUAL image

10. Ray Diagrams for spherical mirrors Rules for drawing a ray diagram: 1.Draw an incident ray parallel to the principal axis, then a reflected ray through the focal point 2.Draw an incident ray through the focal point, then parallel to the principal axis 3.Draw a final line through the center point and back along itself

11. Spherical Mirrors - Concave Image is REAL, INVERTED, and DEMAGNIFIED !!! CF

12. Spherical Mirrors – Concave Object Inside the Focal Point Image is VIRTUAL, UPRIGHT, and MAGNIFIED C F

13. Spherical Mirrors - Convex Image is VIRTUAL, UPRIGHT, and DEMAGNIFIED C F

14. Equations 1/f = 1/d o + 1/d i 1/ focal length = 1/object distance + 1/image distance m = - d i /d o Magnification = - image distance / object distance

15. HomeworkHomework