# Images Formed by Lenses (Page 199) Images formed Images Formed by Lenses (Page 199) 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) Ray Diagrams for Converging & Diverging Lenses

Ray Diagrams for Converging & Diverging Lenses Ray Diagrams for Converging Lenses Ray Diagrams for Converging Lenses

A General Ray Diagram for a Converging Lens F F 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 Image Characteristics of Converging Lenses Case 1: Object between Focal Point and lens 2F

F F 2F

Farther, upright, larger & virtual Case 2: Object between 1 and 2 F 2F F

F Farther, inverted, larger & real 2F

Case 1: Object beyond 2F 2F F F

2F Closer, inverted, smaller & real Ray Diagrams for Converging & Diverging Lenses

Ray Diagrams for Diverging Lenses Ray Diagrams for Diverging Lenses Ray Diagrams for Diverging Lenses

F F Closer, upright, smaller & virtual 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 H.WAll questions on page 561

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