Encyclopedia … combined with a great Buyer's Guide!

Aperture Stops

Definition: apertures which limit the angular range of received input light of imaging systems

German: Öffnungsblenden, Aperturblenden

Categories: general optics, vision, displays and imaging

Author:

How to cite the article; suggest additional literature

URL: https://www.rp-photonics.com/aperture_stops.html

The angular range from which an imaging system can receive light is always limited by some kind of optical aperture, which is called the aperture stop. The mentioned angular range is considered from the central point of the object plane, to which the instrument is focused. Different apertures can play the role of the aperture stop:

  • There can be an optical element (e.g. a lens) of limited size.
  • Alternatively, there may be an intentionally introduced optical aperture, e.g. an iris.
  • In and optical element for direct viewing, for example a telescope or microscope, the effectively usable light may be limited by the pupil of the observing eye.

If an optical system contains multiple apertures, the aperture stop is that aperture which most severely limits the mentioned angular range.

The aperture stop sets a limit to the light gathering power of the instrument. It often needs to be reduced to avoid excessive optical aberrations which would occur for a larger opening angles.

See also: optical apertures, field stops, imaging, f-number, objectives, numerical aperture, entrance and exit pupil

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.

Your question or comment:

Spam check:

  (Please enter the sum of thirteen and three in the form of digits!)

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.

preview

Share this with your friends and colleagues, e.g. via social media:

These sharing buttons are implemented in a privacy-friendly way!

Code for Links on Other Websites

If you want to place a link to this article in some other resource (e.g. your website, social media, a discussion forum, Wikipedia), you can get the required code here.

HTML link on this article:

<a href="https://www.rp-photonics.com/aperture_stops.html">
Article on Aperture stops</a>
in the <a href="https://www.rp-photonics.com/encyclopedia.html">
RP Photonics Encyclopedia</a>

With preview image (see the box just above):

<a href="https://www.rp-photonics.com/aperture_stops.html">
<img src="https://www.rp-photonics.com/previews/aperture_stops.png"
alt="article" style="width:400px"></a>

For Wikipedia, e.g. in the section "==External links==":

* [https://www.rp-photonics.com/aperture_stops.html
article on 'Aperture stops' in the RP Photonics Encyclopedia]