Register
Sign In
Suppliers
Products
Categories
Handbook
Dictionary
Careers
Resources
Photonics Spectra
BioPhotonics
Vision Spectra
Virtual Events & Summits
Educational Institutions
Add/Update Your Listing
Exhibitor Listing Portal
Become an Exhibitor
Buyers' Guide Print Edition
Marketplace Help
Subscribe
Advertise
Suppliers
Products
Categories
Handbook
Dictionary
Careers
Resources
Photonics Spectra
BioPhotonics
Vision Spectra
Virtual Events & Summits
Educational Institutions
Add/Update Your Listing
Exhibitor Listing Portal
Become an Exhibitor
Buyers' Guide Print Edition
Marketplace Help
Register
Sign In
Photonics Marketplace
Suppliers
Products
Handbook
Institutions
Dictionary
Show Filters
Hide Filters
Type
Definitions
Abbreviations/Acronyms
Browse by Letter
#
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
22 terms
Photonics Dictionary
Clear All Filters x
aperture stop x
aperture stop
A physical constraint, often a lens retainer, that limits the diameter of the axial light bundle allowed to pass through a lens.
apodization
The use of a variable transmission filter at the aperture stop of a lens to modify its diffraction pattern. Reduced transmission at the center of the aperture will favor performance at high...
chief ray
The ray that passes through the center of the aperture stop in an optical system. It often is called the principal ray of an oblique beam.
diaphragm
A flanged or plain ring with a restricted aperture, located in an optical system at any of several points, that cuts off marginal light rays not essential to image formation. Diaphragms are used as...
entrance pupil
In a lens or other optical system, the image of the aperture stop as seen from object space.
exit pupil
In a lens or other optical system, the image of the aperture stop as seen from image space.
field stop
An aperture located at an image plane of an optical system that determines the size and shape of the image.
inefficient shutter
A shutter in which the opening and closing times for a large aperture setting occupy a substantial fraction of the total exposure time so that apertures and time pair readings from an exposure meter...
marginal rays
Also referred to as the axial ray (or a-ray), a marginal ray originates from the axial point of the object and passes through the edge or margin of the entrance pupil (or aperture stop) of the lens...
member
In a lens system, a group of elements considered as an entity; either a front or rear member depending on whether it is before or after the aperture stop.
periscopic lens
Two simple meniscus lenses arranged symmetrically on either side of the aperture stop, providing reduced coma, lateral color and distortion.
Petzval lens
A high-speed, narrow-field lens consisting of two achromats spaced about the aperture stop. Its uses include portrait photography and motion picture projection.
pupil
1. In the eye, the opening in the iris that permits light to pass and be focused on the retina. 2. In a lens, the image of the aperture stop as seen from object and image space.
Ramsden circle
->
exit pupil
In a lens or other optical system, the image of the aperture stop as seen from image space.
rapid rectilinear lens
A double meniscus system in which two achromatized meniscus lenses are arranged symmetrically on either side of the aperture stop, reducing or eliminating distortion, coma and lateral color.
rim ray
A ray of an image-forming bundle that passes through the edge of the entrance pupil or aperture stop. Usually used in connection with meridian rays, an upper rim ray is one that passes through the...
Schmidt camera
A camera that consists of a concave spherical mirror with an aspheric plate situated at the center of curvature of the mirror. The purpose of the plate is to correct the spherical aberration of the...
stop down
To reduce the size of a lens aperture, which increases the depth of field.
symmetrical lens
A lens system made up of two sets of similar lenses, each of which compensates for many of the aberrations produced by the other. The lens sets are arranged symmetrically on either side of the...
telecentric lens
There are three types of telecentric lenses: -Image-space telecentric lenses are those in which the aperture stop is located at the front focus, resulting in the chief rays being parallel to the...
telescope exit pupil
The image of the aperture stop, usually the objective lens, that is produced by the eye lens. When the exit pupil of the telescope coincides with the entrance pupil of the eye of the observer, the...
upper rim ray
->
rim ray
A ray of an image-forming bundle that passes through the edge of the entrance pupil or aperture stop. Usually used in connection with meridian rays, an upper rim ray is one that passes through the...
Photonics Dictionary
Need Help?
Explore Our Content
News
Features
Latest Products
Webinars
White Papers
All Things Photonics Podcast
Videos
Our Summits & Conferences
Industry Events
Bookstore
Join Our Community
Subscribe
Advertise
Become a member
Sign in
Contribute a Feature
Suggest a Webinar
Submit a Press Release
Mobile Apps
About Us
Our Company
Our Publications
Contact Us
Career Opportunities
Teddi C. Laurin Scholarship
Terms & Conditions
Privacy Policy
California Consumer Privacy Act (CCPA)
©2024 Photonics Media
100 West St.
Pittsfield, MA, 01201 USA
[email protected]
We use cookies to improve user experience and analyze our website traffic as stated in our
Privacy Policy
. By using this website, you agree to the use of
cookies
unless you have disabled them.