Post on 14-Feb-2016
description
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
Convex Lens Formation
Convex Lens Formation
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