1. Lenses

2. Converging Lens Diverging Lens Lens Characteristics • Lenses are objects that refract light rays. • Two refracting surfaces • Rays will either converge or diverge to create an image. • Two Types:

3. Lens Characteristics f f f f

4. Converging Lenses • Produce either real or virtual images • Object distance > f = real image, opposite side • Object placed closer than f = virtual image, same side • Object placed at infinity = point image on opposite f (ex. Sun & magnifying glass) • Object at f = image at infinity (ex. Lighthouses)

5. f f Ray Diagram (Converging Lens) 1 THE HUMAN EYE 2 3 P-Axis Image • In parallel to P-axis, out to f point 2. To center of lens, out center of lens 3. Passes through f, out parallel to P-axis

6. f f Ray Diagram (Converging Lens) 3 1 Image P-Axis 2 Binoculars, microscopes, & telescopes

7. Diverging Lenses • Only produces virtual images on the same side as the object. • Used to correct nearsightedness

8. f f Ray Diagram (Diverging Lens) 1 3 Image 2 • In parallel to P-axis, out away from f point 2. To center of lens, out center of lens 3. Travels towards opposite f, out parallel to P-axis

9. Thin Lens Equation • Is identical to the mirror equation and can be used for both convergent and divergent lenses. 1 + 1 = 1 p q f + q = image behind lens - q = image in front of lens + f = converging lens - f = diverging lens

10. Magnification of a Lens • Formula is also identical to mirror magnification formula: M = h´= - q h p + M = virtual, upright image - M = real, inverted image