 Review Lenses

Web Resources

 Resource lessons: Converging Lenses Diverging Lenses Thin Lens Equation
 Alert: This is a required review activity: CP Workbook:  Lens properties
 Ray Diagram Labs: Converging Lenses (6 cases) Diverging Lenses (2 cases)
 Worksheets: Thin Lens Equation #1 Thin Lens Equation #2 Thin Lens Equation #3 Thin Lens Equation #4 Thin Lens Equation #5 Converging Lens Vocabulary Diverging Lens Vocabulary

Equations  n = c / v        n = lvac / lmed       n1 sin q1 = n2 sin q2        vw = fl

Summary

Converging Lenses Diverging Lenses
shape "caved in" "bowed out"

position of principal focus

F is "behind the lens"
on the opposite side of the lens as the incoming light
F is "in front of the lens"
on the same side of the lens as the incoming light
image
position
1/do + 1/di = 1/f
do is always positive
d
i is positive if real
d
i is negative if virtual
f is positive (convex)
1/do + 1/di = 1/f
do is always positive
d
i is always negative (virtual)
f is negative (concave)
image
properties
varies with do
six case ray diagrams
 do ® Ą di = f real M 0 do > 2f 2f < di < f real M < 1 do = 2f di = 2f real M = 1 2f < do < f di > 2f real M > 1 do = f no image is formed - - - - do < f 0 < di < - Ą virtual M > 1

virtual, upright, M < 1
ray diagrams
 do ® Ą di = -f virtual M 0 any do < Ą 0 < di < -f virtual M < 1
magnification M = | di / do | = | I / O | M = | di / do | = | I / O |
rays #1 top of the object, parallel to the axis, strikes the lens, refracts through F

#2 top of the object, passes through the center of the lens unbent

#3 top of the object, aims for F', strikes the lens, refracts parallel to the axis

#1 top of the object, parallel to the axis, strikes the lens, refracts through F (dot in line to F)

#2 top of the object, passes through the center of the lens unbent

#3 top of the object, aims for F', strikes the lens, refracts parallel to the axis (dot back refracted ray)