Photonics Dictionary

A camera that permits adjustments in the perspective of an image; this is accomplished by the camera design, which permits tilt, swing, rise or fall of the image transmitted. Also known as a...

A device, optical or electronic, that may be joined to a camera so that the operator may perceive the scene as the camera does.

A filter, pale purple in color, used in black and white photography to display the brightness values of a subject being recorded on film.

A viewfinder whose optical system forms a direct image of a subject, as opposed to those systems that use reflectance in the image formation.

The observation of a reproduced television picture on the face of a cathode-ray tube.

A cathode-ray tube in which secondary emission electrons form a display of high intensity.

A small television monitor that replaces the reflex viewfinder in a television camera.

The field of view (FOV) refers to the extent of the observable world or the visible area that can be seen at any given moment through a device, such as an optical instrument, camera, or sensor. It is...

A device small enough to be held in a hand that uses a magnifying lens and a translucent back to permit the viewing of photographic transparencies.

Instantaneous field of view (iFOV) is a term commonly used in the context of remote sensing, imaging systems, and optical instruments. It refers to the specific portion of a scene that an optical...

With respect to laser radiation, the subjection of the human eye to all or a portion of the laser beam.

A passive infrared system that uses two line-of-sight telescopes to generate both narrow and wide field-of-view images of the same target area, which can be presented on a single split screen or on...

A viewer that uses the transmittance of polarized light through glass or a similar medium to examine strained regions. See polariscope.

A 2D profile sensor is a type of sensor used in various industrial and technological applications to measure and capture detailed information about the shape, contour, or profile of an object in two...

imaging system which clearly shows the IR signals in the field of view as well as ambient environment

Advanced driver assistance systems (ADAS) refers to a set of safety features and technologies designed to assist drivers in the driving process and enhance overall vehicle safety. These systems use...

An image that can be studied three-dimensionally through a pair of complementary color filters composed of two superimposed views.

A cylindrical convex viewing mirror used for viewing distorted pictures formed by photographing the reflections of the objects in a similar type of mirror.

Aplanatic points refer to specific points in an optical system where certain aberrations, such as spherical aberration or coma, are minimized or eliminated. In an optical system, aberrations are...

The angular subtense of the field of view in the image space of a telescope, as differentiated from that in the object space (the true field).

The perceived brightness of an object being viewed at some distance, especially through an optical instrument.

The angle subtended by an object, determined by the size of the object and its distance from the viewer.

Area scan, in the context of imaging and cameras, refers to a method of capturing an entire two-dimensional image in a single snapshot or exposure. Unlike line scan, which captures images one line at...

An astronomical telescope is a type of optical instrument designed to gather and magnify light from distant celestial objects for observation and analysis. It typically consists of two main optical...

Augmented reality (AR) is a technology that integrates digital information, typically in the form of computer-generated graphics, images, or data, with the real-world environment in real-time. AR...

The strongest light emitted by the Earth's upper atmosphere. It most often can be viewed in the Arctic as the aurora borealis, and in the Antarctic as the aurora australis.

An autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on the principle of autocollimation, where a light source is directed onto a...

In astronomy, the method of deliberately viewing objects with peripheral vision to take advantage of the eye's greater sensitivity to faint light a few degrees from the optical center.

The intensity of the light in the scene behind an object being viewed.

Unified notation for specification of reflectance in terms of both incident- and reflected-beam geometry; i.e., the ratio of reflected radiance in direction toward the viewer to the irradiance in...

Designating any instrument in which both eyes can be used to view the image to achieve a stereoscopic effect, or merely to facilitate observation. See also prism binoculars.

The glossy appearance of an object viewed, because of the binocular combination of two very unlike colors.

A microscope designed with two eyepieces (oculars), permitting the use of both eyes when viewing through the instrument.

The ability of the two eyes to see an object from two slightly different points of view. This difference allows an individual to perceive the depth and dimension of the object in view.

A term pertaining to devices (generally optical) designed for use with both eyes viewing through a single exit pupil. The term may be distinguished from binocular in that biocular instruments contain...

Light interference fringes that can be viewed on a screen near a biprism.

Birefringence is an optical property of certain materials that causes them to exhibit different refractive indices for light of different polarizations. In other words, when light passes through a...

In ophthalmic practice, an instrument that determines the boundaries of the field of view. It is composed of a 2-m square of black velvet with a white spot center at which the patient, 1 m away,...

The simplest, most inexpensive type of camera, which is shaped as an oblong or square box, containing the simplest lens, shutter and viewfinder, as well as the most elementary means of registering...

A cathode-ray tube, driven by a computer, that receives impulses of information from the computer and displays it in a series of lines, circles, curves or other graphic forms to be viewed by the user.

That viewpoint at which the angular subtenses of points in the picture are identical to angular subtenses of the original points in the scene, at the camera lens.

A compound prism consisting of an assembly of small prisms cemented together that is used in a coincidence rangefinder to transmit the images from the two objectives to a single eyepiece for viewing.

An optical instrument used to determine the distance to a target being viewed. Two similar optical systems view the target via 45° mirrors at the ends of a fixed baseline. One system creates the...

That part of an infrared detector-Dewar assembly that limits the solid angle viewed by the sensor; it is maintained at a uniformly cold temperature so that no thermal energy is emitted. Also known as...

1. A device used in chemistry to compare the colors of solutions held in flat-bottomed tubes and viewed along the length of the tube. Often a solid glass plunger is moved along one of the tubes to...

Two microscopes that are coupled on a common stand, the two images being projected side by side in the field of view of a single eyepiece for comparison.

Concave and convex spherical mirrors are types of curved mirrors that have surfaces shaped like segments of spheres. These mirrors are commonly used in optics for various applications, including...