Converging Lenses&

Their Application

Dan LiSUNY-Stony Brook

11/07/2002

OUTLINEThin Lenses

Converging lenses Focal length & Geometric Construction Thin Lens Equation

Applications Cameras Projector Simple Magnifier

What Are ThinLenses?

What Are TheyUsedTo do?

Focal LengthFocal PointFocal LengthSymbol: fTwo Focal Point Two Focal LengthSame Focal Length

Geometric Construction A ray passing through the center is un-deviated.A ray which is parallel to the principal axis of the lens will pass through the focal point after refraction.

Thin-lens Equation

o: object distancei: image distancef: focal lengthM=-i/o : magnification

                                                           

  

The Relation between Object & Image

1 Obj>2f f<Ima<2f -1<M<02 f<Obj<2f Ima>2f M<-1 3 0<Obj<f Ima<0 M>1

Cameras

How Cameras Work

Projector

How Projector Works

Simple Magnifier

How Magnifier Works

More Applications

Thank you!