Cardinal Points
Definition: a set of points which characterize the function of an optical element or a group of elements in Gaussian optics
German: Hauptpunkte
How to cite the article; suggest additional literature
Author: Dr. Rüdiger Paschotta
Various types of cardinal points are defined in Gaussian optics for characterizing the optical function of a single optical element or a group of such elements:
- There are the front and back focal points at the intersection of the focal planes with the optical axis.
- The principal points are at the intersections of the principal planes with the optical axis.
- Further, there are the front and back nodal points.
The cardinal points can be calculated from the ABCD matrix, and vice versa. They are useful, for example, when geometrically constructing images of objects.
According to the basic assumptions of Gaussian optics, the rays are considered for the limiting case of small angles against the optical axis. If parallel incoming rays are calculated for a wider range of offsets, for example, will generally not exactly meet in a focal point.
Questions and Comments from Users
Here you can submit questions and comments. As far as they get accepted by the author, they will appear above this paragraph together with the author’s answer. The author will decide on acceptance based on certain criteria. Essentially, the issue must be of sufficiently broad interest.
Please do not enter personal data here; we would otherwise delete it soon. (See also our privacy declaration.) If you wish to receive personal feedback or consultancy from the author, please contact him, e.g. via e-mail.
By submitting the information, you give your consent to the potential publication of your inputs on our website according to our rules. (If you later retract your consent, we will delete those inputs.) As your inputs are first reviewed by the author, they may be published with some delay.
See also: Gaussian optics, focal points and focal planes, principal points and principal planes, nodal points
and other articles in the category general optics
 |
Share this with your friends and colleagues, e.g. via social media:
These sharing buttons are implemented in a privacy-friendly way!