Worlds of David Darling
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A representation of an object formed by rays of light or other electromagnetic radiation in an optical instrument such as a telescope, microscope, or camera. A real image has rays of light passing through it and is formed by points to which the rays from the object converge. Rays of light do not pass through the points composing a virtual image: the image lies at the place from which the light rays, if traced backwards, appear to diverge. A virtual image, such as that produced by a plane mirror, has no physical existence, whereas a real image can be projected onto screen and recorded, for examplein the form of photographic emulsion.

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