1. Ch. 18 Mirrors and Lenses Milbank High School

2. Sec. 18.1 Mirrors Objectives –Explain how concave, convex, and plane mirrors form images. –Locate images using ray diagrams, and calculate image location and size using equations. –Explain the cause of spherical aberration and how the effect may be overcome. –Describe uses of parabolic mirrors.

3. Plane Mirrors Plane mirrors Object Images Virtual Image

5. Concave Mirrors Reflects light from its inner “caved in” surface Principal axis Focal point Focal Length Real Images

6. Concave Mirrors Real, inverted images if object is farther from the mirror than the focal point

8. Calculations… Lens/Mirror Equation: Magnification: Example problem Pg. 422 –Calculating the Real Image Formed by a Concave Mirror Example problem Pg. 424 –A Concave Mirror as a Magnifier d i is distance from the image to the mirror d 0 is the distance from the object to the mirror f is focal length of the mirror

9. Convex Mirrors Reflects light from its outer surface, always diverge No real image, upright Reduced in size (wide angle mirrors)

10. Calculations… Use same Lens/Mirror Equation –Focal length is negative –d i is negative (image is behind the mirror) Pg. 427 Pr. 6

11. Sec. 18.2 Lenses Objectives –Describe how real and virtual images are formed by convex and concave lenses. –Locate the image with a ray diagram and find the image location and size using a mathematical model. –Define chromatic aberration and explain how it can be reduced. –Explain how optical instruments such as microscopes and telescopes work.

12. Types of Lenses Lens Convex lens Concave lens

13. Convex lenses (converging lenses) Produce real, inverted images if the object is farther from the lens than the focal point If object is closer than the focal point, a virtual, upright, enlarged image is formed

14. Concave Lenses (diverging lenses) Produce virtual, upright, reduced images

15. Calculations… f is positive for convex lenses f is negative for concave lenses d o is positive on the object side of the lens d i is positive on the other side (image side) of the lens, where images are real d i is negative on the object side of the lens where images are virtual Ex. Prob. Pg 431 Ex Prob. 434