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Wikipedia

Virtual image

"Virtual object" redirects here. For the representation of objects in computers, see Virtualization. For digital-media objects, see Virtual artifact.

In optics, an image is defined as the collection of focus points of light rays coming from an object. A real image is the collection of focus points made by converging rays, while a virtual image is the collection of focus points made by extensions of diverging rays. In other words, 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 ray divergences. In diagrams of optical systems, virtual rays are conventionally represented by dotted lines.

Top: The formation of a virtual image using a diverging lens. Bottom: The formation of a virtual image using a convex mirror. In both diagrams, f is the focal point, O is the object and I is the image, shown in grey. Solid blue lines indicate light rays. It can be seen on the right that the light rays appear to emanate from the virtual image but do not actually exist at the position of the virtual image. Thus an image cannot be seen by placing a screen at the position of the virtual image.

Because the rays never really converge, a virtual image cannot be projected onto a screen. In contrast, a real image can be projected on the screen as it is formed by rays that converge on a real location. A real image can be projected onto a diffusely reflecting screen so people can see the image (the image on the screen plays as an object to be imaged by human eyes)

  • A plane mirror forms a virtual image positioned behind the mirror. Although the rays of light seem to come from behind the mirror, light from the source only exists in front of the mirror. The image in a plane mirror is not magnified (that is, the image is the same size as the object) and appears to be as far behind the mirror as the object is in front of the mirror.
  • A diverging lens (one that is thicker at the edges than the middle) or a convex mirror forms a virtual image. Such an image is reduced in size when compared to the original object. A converging lens (one that is thicker in the middle than at the edges) or a concave mirror is also capable of producing a virtual image if the object is within the focal length. Such an image will be magnified. In contrast, an object placed in front of a converging lens or concave mirror at a position beyond the focal length produces a real image. Such an image may be magnified or reduced depending on the position of the object.
  1. Knight, Randall D. (2002). Five Easy Lessons: Strategies for successful physics teaching. Addison Wesley. pp. 276–278.

Virtual image
Virtual image Language Watch Edit Virtual object redirects here For the representation of objects in computers see Virtualization For digital media objects see Virtual artifact In optics an image is defined as the collection of focus points of light rays coming from an object A real image is the collection of focus points made by converging rays while a virtual image is the collection of focus points made by extensions of diverging rays In other words 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 ray divergences In diagrams of optical systems virtual rays are conventionally represented by dotted lines Top The formation of a virtual image using a diverging lens Bottom The formation of a virtual image using a convex mirror In both diagrams f is the focal point O is the object and I is the image shown in grey Solid blue lines indicate light rays It can be seen on the right that the light rays appear to emanate from the virtual image but do not actually exist at the position of the virtual image Thus an image cannot be seen by placing a screen at the position of the virtual image Because the rays never really converge a virtual image cannot be projected onto a screen In contrast a real image can be projected on the screen as it is formed by rays that converge on a real location A real image can be projected onto a diffusely reflecting screen so people can see the image the image on the screen plays as an object to be imaged by human eyes 1 A plane mirror forms a virtual image positioned behind the mirror Although the rays of light seem to come from behind the mirror light from the source only exists in front of the mirror The image in a plane mirror is not magnified that is the image is the same size as the object and appears to be as far behind the mirror as the object is in front of the mirror A diverging lens one that is thicker at the edges than the middle or a convex mirror forms a virtual image Such an image is reduced in size when compared to the original object A converging lens one that is thicker in the middle than at the edges or a concave mirror is also capable of producing a virtual image if the object is within the focal length Such an image will be magnified In contrast an object placed in front of a converging lens or concave mirror at a position beyond the focal length produces a real image Such an image may be magnified or reduced depending on the position of the object See also EditFocal plane Image plane Lens Real imageReferences Edit Knight Randall D 2002 Five Easy Lessons Strategies for successful physics teaching Addison Wesley pp 276 278 Retrieved from https en wikipedia org w index php title Virtual image amp oldid 1051747067, wikipedia, wiki, book,

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