Real picture
Real image is a term from geometric optics . It describes images from which really (in “reality”, therefore real ) rays of light emanate. At the location of the real image there can be a screen from which rays of light emanate that have met there ( screen image). If the screen is missing, the light rays diverge again and can be perceived directly when they hit the eye (spatial image).
When an object is mapped from the object space, it can be transferred into the image space as a real image. A real intermediate image can in turn be transferred as an object into a further image space.
The opposite is the virtual image , which can never be displayed on a screen, but can only be made visible, for example, with an eye or a camera .
Examples
Important examples of real images are:
- The picture in a pinhole camera .
- The image that a converging lens or objective produces of an object farther from its principal plane than the focal length indicates. Depending on the image scale , the real image can be smaller, equal to or greater than the object.
- The image on the screen of a television set ; here, however, no rays of light fall on the screen, but are generated there.
- The image of a light source in the illumination beam path in the main plane of the imaging beam path in the case of the concatenated beam path .
literature
- Eugene Hecht: Optik , Oldenbourg, 4th edition 2005, ISBN 3-486-27359-0