Focal length

1
Lenses

• Focal length

Focal length
Focal length
F
F
Focal length is the same on both sides of the lens
2
Lenses

• Other words you need to know about lenses

Object
Image distance (i)
Axis
Object distance (o)
Image
Lens
3
Lenses

• The three standard rays

F
F
4
Lenses

• Linear magnification the formula

 

 
3 cm
9 cm
5
Lenses

• Make a virtual image (magnifying glass)

F
F
6
Lenses

• Calculations on virtual images (VWO only)

M 2,5 o 2 cm
 
i ?
i -5 cm