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. Source Wikipedia
In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Source Wikipedia
A real image occurs where rays converge, whereas a virtual image occurs where rays only appear to diverge. Source Wikipedia
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. Source Wikipedia
A real image ... is an image which is located in the plane of convergence for the light rays that originate from a given object. Source Wikipedia
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. Source Wikipedia
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. Source Wikipedia
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. Source Wikipedia
In diagrams of optical systems, virtual rays are conventionally represented by dotted lines. Source Wikipedia
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. Source Wikipedia
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. Source Wikipedia
In optics, an image is defined as the collection of focus points of light rays coming from an object. Source Wikipedia
An eyepiece is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. Gallery Tutorial TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model Section Slide kind SysML Block Definition Diagram (BDD)
In optical engineering, the objective is the optical element that gathers light from the object being observed and focuses the light rays to produce a real image. Source Wikipedia
The objective is the optical element that gathers light from the object being observed and focuses the light rays Gallery Tutorial TRAIL: Webel SysML Parsing Analysis example: Optical telescopes from Wikipedia: Structure and port-based light flow model Section Slide kind SysML Block Definition Diagram (BDD)
