Conceptual Physics

Ray 2 passes through the lens without changing direction.

Ray 3 must refract to be horizontal on the far side of the lens. The forward extension of the incident portion of this ray is a virtual ray passing

through the focal point on the far side. The backward extension of the refracted portion of the ray is a virtual ray parallel to the principal axis on

the object side of the lens.

As the illustration below shows, the image is upright, smaller than the object, and virtual. This is the case for all images produced by a single

diverging lens.

The example to the right leads you through another ray tracing exercise for a diverging lens. The object in the example is closer to the lens

than the one above.

Ray 2

Straight through center of lens

Ray 3

Virtual ray through far focal point, virtual

ray parallel to axis

Image

Upright, smaller, virtual

Determine the size and location

of the image.

Draw ray 1

Draw ray 2

Draw ray 3

Image is upright, smaller, virtual

(^610) Copyright 2007 Kinetic Books Co. Chapter 33