IMAGE FORMATION IN PLANE MIRROR

The precise direction of the sight line depends on the location of the object, the location of the person, and the type of mirror. Yet all of the lines of sight, regardless of their direction, will pass through the image location. In fact, the image location is defined as the location where it seems to every observer as though light is coming from. Since all people see reflected rays of light as they sight at an image in the mirror, then the image location must be the intersection point of these reflected rays.

 In the animation above, an object is positioned in front of a plane mirror. The plane mirror will produce an image of the object on the opposite side of the mirror. The distance from the object to the mirror equals the distance from the image to the mirror. Any person viewing this image must sight at this image location. The animation depicts the path of several rays of light from the object to the mirror. This light subsequently reflects such that observers could sight along a line of sight and view the image. Different people might sight from different locations; yet each person would sight at the same image location. As seen in the animation, the image location is the intersection point of all the reflected rays.