Photonics Dictionary

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...

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...

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 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

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).

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...

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,...

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...

Fine lines, wires or threads used in the focal plane of many optical instruments to point out and locate particular objects in the field of view. They were formerly made from a single strand of...

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...

A telescope stand equipped with a polar axis that can be set parallel to the Earth's axis of rotation and a declination axis that is at right angles to the polar axis. If the telescope is turned at a...

One or more spots placed in the field of view of an optical system to provide a means of reference.

1. In raster scan television, one of the two scans that are interlaced to make up a frame. 2. See field of view.

1. A lens situated at or near the plane of an internal image to project the aperture of a previous objective or erector upon the aperture of a following lens. 2. A lens at or near the plane of a...

A low-power telescope with a wide field of view, typically attached to a higher power telescope with a narrower field of view. This enables an observer to locate a celestial object with the...

Fizeau fringes are interference fringes observed in an interferometer, specifically in a Fizeau interferometer. The Fizeau interferometer is named after the French physicist Armand Fizeau, who...

A reticle whose image may be moved about in a field of view.

The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or film when the lens is focused at infinity. In simple terms, it is the...

The restricting aperture located at the front of the lens. It is usually defined as the maximum diameter of the entrance cone at the front vertex, for the specified field of view at infinity focus.

An optical system that superimposes a synthetic display providing navigational or weapon-aiming information on a pilot's or driver's field of view. The system includes a cathode-ray tube, collimating...

In optics, the term image jump refers to a displacement or shift in the apparent position of an image when a change occurs in the optical system. This phenomenon is often observed in certain types of...

An infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating infrared (IR) radiation within the infrared spectrum. These lenses are used in...

A computer-generated kinoform used for data processing because of its use of incoherent light and its wide field of view, which facilitates parallel processing of two-dimensional data.

Lensless microscopy, also known as computational or holographic microscopy, is an imaging technique that captures and reconstructs microscopic images without the use of traditional lenses. Instead of...

The measured width of the field of view at any distance.

A small half-shade analyzer placed in the eyepiece of a polarimeter to determine the character of the polarized light emitted by the instrument. It consists of a Nicol prism situated so that it...

A machine vision lens is a specialized optical lens designed for use in machine vision systems, which are used for automated inspection, measurement, and quality control in industrial applications....

Machine vision lighting refers to the use of specific lighting techniques and equipment in the field of machine vision, which is a technology that enables machines to capture and interpret visual...

A machine vision system is an integrated combination of hardware and software components designed to capture, process, and analyze images to perform automated inspection, measurement, and quality...

The ability of an optical system to make an object appear larger. An optical element or optical system causing an object to appear twice as high and twice as wide is said to have a magnification of...

A group of photosensors arranged in a grid-like pattern covering the entire field of view, enabling them to record it all at once (as a camera records an image on film) rather than by scanning parts...

In a remote sensing system, nadir refers to the point on the ground located vertically below the center of the system. In astronomy, the nadir is the vertical direction that points towards the force...

1. A prism used in some instruments to bend light 90° before it enters the objective. 2. A dispersing prism located in front of an astronomical telescope objective to produce spectra of all...

An optical combiner, in the context of optics and display technologies, refers to a device or component that combines multiple optical signals or images into a single output. The purpose of an...

1. The angular displacement of the plane of polarization of light passing through a medium. 2. The azimuthal displacement of the field of view achieved with a rotating prism.

An optical testing instrument is a device or system used to evaluate and measure the performance, quality, and characteristics of optical components, systems, and devices. These instruments play a...

A camera designed with a telecentric optical system and a narrow field of view; the telecentric optical system (placement of the system's stop at its focal point) ensures that the principal image...

A telescopic eyepiece that produces a field of view between 40° and 50°. The eyepiece consists of a single element eyelens that is normally plano convex, and a cemented triplet that is...

A lensless photographic camera that uses a small sharp-edged hole as its aperture. The light passed by this aperture onto the camera's film plane produces a soft-edged image that has a wide field of...