Magnification
In general with spherical mirrors the image is a different size than the object. The magnification, m, is defined as the ratio of the image height to the object height:
| m |
= |
| hi
|  |
| ho
|
|
= - |
| di
| |
| do
|
|
A magnification of 1 (plus or minus) means that the image is the same size as the object. If m has a magnitude greater than 1 the image is larger than the object, and an m with a magnitude less than 1 means the image is smaller than the object. If the magnification is positive, the image is upright compared to the object; if m is negative, the image is inverted compared to the object.