Audio Guide：

A concave mirror can collect all reflected light on one point, which is called the “focus.” The relative distance between an object and the focus determines the imaging quality. When the object is within the focus, an upright, enlarged virtual image will be produced. On the other hand, if the object is outside the focus, an inverted real image will be produced.

Visitors can get to know more about the imaging principles of a concave mirror through the textual introduction with pictures.