Chapter 18 Mirrors and Lenses

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

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

Mirrors Plane Mirror: Flat, smooth surface where light is reflected by specular reflection and not diffuse

Flat Plane Mirror Image reversed Left- Right Image formed equal distance behind mirror Image is Virtual – Rays don’t converge

Real and Virtual

Real verse Virtual Since real images do converge, they can be projected onto a screen. Virtual images can not be projected, because rays don’t converge

Concave Mirrors Curved in Focal point is where parallel rays would converge – Always ½ curvature

Concave Mirrors/Convex Lens

Image Formed at Intersection

Convex Lens Formation

More on Eye

Spherical Aberration When the mirror/lens has defects which cause parallel rays NOT to converge at the focal point Mirrors tend to be easier to make more precise then lens due to size limitations of lens

Chromatic Aberration Due to light waves refracting differently, get blurred image at edges of lens To fight this, use two lenses, one of each, to cancel effects