Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content Optics: real images vs virtual images and focus points Source Wikipedia Copyright information Text from Wikipedia and Wiktionary web pages quoted for educational purposes is subject to the Wikipedia Creative Commons Attribution ShareAlike Licence Snippet kind INFO Keywords optics image light ray focus point focus image point Previous snippet Full quote In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. URL https://en.wikipedia.org/wiki/Focus_(optics) Next snippet Related snippets 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 actually made by converging rays, while a virtual image is the collection of focus points made by extensions of 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 ray divergences. In diagrams of optical systems, virtual rays are conventionally represented by dotted lines. 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 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. A real image ... is an image which is located in the plane of convergence for the light rays that originate from a given object. In ray diagrams ... real rays of light are always represented by full, solid lines; perceived or extrapolated rays of light are represented by dashed lines. Related snippets (backlinks) Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by aberrations of the imaging optics. Visit also Visit also (backlinks) Flags
