According to the The Encyclopedia Britannica, an optical image is
the apparent reproduction of an object, formed by a lens or mirror system from reflected, refracted, or diffracted light waves. There are two kinds of images, real and virtual. In a real image the light rays actually are brought to a focus at the image position, and the real image may be made visible on a screen -- e.g., a sheet of paper -- whereas a virtual image cannot.
Examples of real images are those made by a camera lens on film or a projection lens on a motion-picture screen. Britannica Online.
But virtual images . . .
Last updated: 20 July 2002