A Brief Introduction:

Lenses and mirrors are used everyday.  People wear glasses to correct their vision.  Mirrors are used to see behind ourselves.
But which lens or mirror is right for the job?

A lens or mirror can come in three types: plane, concave, and convex.
A plane mirror or lens is flat and does not change the height, distance, or orientation of the image.
Both concave and convex mirrors and lenses can change the height, distance, and orientation of the image based upon the objects location.
The easiest way to find how a mirror or lens will affect the appearence of the image is to use a ray-diagram.

Some important things to know:

The focal distance is one half of the radius of the lens or mirror:

f = R/2

The center of curvature (C) is at a distance equal to the radius from the mirror.

The height of the object is ho, the height of the image is hi.  The distance from the object to the mirror is do, the distance from the mirror to the image is di.

All mirrors work using the law of reflection: the angle of incidence (Theta i) is equal to the angle at which the image is reflected (Theta r).

Magnification is found by dividing the height of the image by the height of the object.


This is from reading Bauer and Westfall, Chapters 32 and 33.

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