Virtual image determination for mirrored surfaces.

An object viewed via reflection from a mirrored surface is often perceived by the observer to be located behind the mirror's surface. The image of this object behind the mirror is known as its virtual image. Conventional methods for determining the location and shape of a virtual image for non-planar mirrors are complex and impractical unless both the observer and object are near the optical axis. We have developed a technique designed to be simple and practical for determining the location of a virtual image in a non-planar mirror far from the optical axis. Results using this technique were compared with known results from geometric optics for an object point on the optical axis of a parabola and for an object point imaged off the optical axis of a spherical mirror. These results were also in agreement with experimental measurements for a hemispherical mirror viewed at large angles with respect to its optical axis. This technique has applications for display devices or imaging tools utilizing curved, mirrored surfaces.