Virtual image

Collection of focus points made by extended diverging light rays

In optics, the image of an object is defined as the collection of focus points of light rays coming from the object. A real image is the collection of focus points made by real converging rays, while a virtual image is the collection of focus points made by backward extensions of real diverging rays. A virtual image is found by tracing real rays, that emerge from an optical device (lens, mirror, or some combination), backward to perceived or apparent origins of real ray divergences.

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