A simple but effective device for demonstrating the symmetrical nature of plane surface reflection. It consists of a tinted Perspex screen, 150 x 100mm, provided with side supports.
If the mirror is placed on a sheet of paper with an object in front of it, the reflected virtual image is seen in the usual way. However, unlike a normal mirror, the transparent perspex permits real objects in the area apparently occupied by the image to be seen also. It is therefore possible to make accurate measurements on, or trace around the virtual image and thus demonstrate the symmetry that exists.