Editing Real image (section)

{{Short description|Collection of focus points made by converging light rays}}
{{citations needed|date=June 2019}}
[[File:Real image.svg|thumb|right| Top: The formation of a real image using a convex lens. Bottom: The formation of a real image using a concave mirror. In both diagrams, ''f''&nbsp; is the [[Focus (optics)|focal point]], ''O''&nbsp; is the object, and ''I''&nbsp; is the image. Solid blue lines indicate light rays. It can be seen that the image  is formed by actual light rays and thus can form a visible image on a screen placed at the position of the image.]]

[[File:Convex lens (magnifying glass) and upside-down image.jpg|thumb|341x341px|An inverted real image of distant house, formed by a convex lens, is viewed directly without being projected onto a screen.]]

[[File:realimageondetector.svg|thumb|384px|right|Producing a real image. Each region of the detector or retina indicates the light produced by a corresponding region of the object.]]

In [[optics]], an ''image'' is defined as the collection of [[Focus (optics)|focus point]]s of [[ray (optics)|light rays]] coming from an object. A '''real image''' is the collection of focus points actually made by converging/diverging rays, while a [[virtual image]] is the collection of focus points made by extensions of [[Beam divergence|diverging]] or converging rays. In other words, a real image is an image which is located in the plane of convergence for the light rays that originate from a given object. Examples of real images include the image produced on a [[Photodetector|detector]] in the rear of a [[camera]], and the image produced on an eyeball [[retina]] (the camera and eye focus light through an internal convex lens). 

In ray diagrams (such as the images on the right), real rays of light are always represented by full, solid lines; perceived or extrapolated rays of light are represented by dashed lines. A real image occurs at points where rays actually converge, whereas a virtual image occurs at points that rays appear to be diverging from.

Real images can be produced by [[concave mirror]]s and [[Convex Lens|converging lenses]], only if the object is placed further away from the mirror/lens than the focal point, and this real image is inverted. As the object approaches the focal point the image approaches infinity, and when the object passes the focal point the image becomes virtual and is not inverted (upright image). The distance is not the same as from the object to the lenses.

Real images may also be inspected by a second lens or lens system. This is the mechanism used by [[optical telescope|telescope]]s, [[binoculars]] and [[light microscope]]s. The objective lens gathers the light from the object and projects a real image within the structure of the optical instrument. A second lens or system of lenses, the [[eyepiece]], then projects a second real image onto the retina of the eye.

<!-- [No idea what this paragraph was included to convey; possibly a dangling image caption] A real image can be viewed when a screen is placed in the plane of convergence; alternatively, one may also view the real image directly (see the picture below captioned "An inverted real image of distant house..."). When viewed directly, the real image looks like a "phantom object" that's closer to the viewer than the lens itself, which can be verified if the viewer uses the method of [[parallax]].  -->