Photonics Dictionary: A

Method of preserving the measured color value and color information as it is translated from differing devices. For example the output of a television display may be measured to have an identical...

Process in which two or more lights are combined by superposition.

A process of color photography in which colors are added one to another in the form of light, rather than as colorants, to obtain color synthesis.

Method for studying absorption coefficients of low-loss materials, in which a sample is allowed to come to thermal equilibrium with its surrounding blackened enclosure. The sample is irradiated with...

A lens aberration that causes axial light rays having different wavelengths to focus at various points along the axis.

The alteration and reduction of color with the addition of white light. The perceived color shift that occurs as the monochromatic-white combination meets the eye and is interpreted by the brain. The...

Least value of color value combinations which gives white light; minimum purity as determined to be white.

An achromat, in the context of optics, refers to a type of lens or lens system designed to reduce chromatic aberration. Chromatic aberration is an optical phenomenon where different colors of light...

Color correcting; chromatic aberration corrected.

Location on the CIE chromaticity diagram which produces the color white for a given light source at a specified temperature.

Use of achromatic design; the correction of chromatic aberration; without color or hue (grey, black and white)

An intermolecular substance that serves to hold materials together. Two types are used in the optical industry: one, which must be transparent and colorless, to cement lenses together; and a...

A chemical placed in a solution that will indicate when an excess of a substance or ion has been reached by coloring the precipitate after the chemical itself has been totally adsorbed.

That image remaining on the detector after the primary stimulus has been removed. In the visual system, the after-image commonly appears as the complementary color of the primary stimulus.

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

The angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence.

An optical instrument that uses a yellow light of varying intensity with red and blue lights of fixed intensity to test for colorblindness.

Color vision whereby abnormal proportions of three colors are needed for color matching.

An antireflection coating (AR coating) is a thin film or coating applied to optical surfaces, such as lenses or windows, to minimize unwanted reflections and increase the transmission of light...

Also known as a shadow mask, a perforated plate placed between the focusing and accelerating electrodes, and the tricolor phosphor screen in a color-television tube.

A physical constraint, often a lens retainer, that limits the diameter of the axial light bundle allowed to pass through a lens.

An apochromat, often referred to as an apochromatic lens or apochromatic objective, is a type of optical system designed to minimize chromatic aberration. Chromatic aberration occurs when different...

An optical system that is corrected chromatically for three colors simultaneously.

A lens aberration that results in the tangential and sagittal image planes being separated axially.

Any irregular motion, variation in intensity or change in color that arises because of atmospheric turbulence during the observation of an astronomical phenomenon or object.

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...

An atomic absorption spectrometer (AAS) is an analytical instrument used to determine the concentration of specific chemical elements in a sample by measuring the absorption of light at...

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...

A system for automatic industrial process control or measurement, consisting of an optical module for image acquisition, a segmentation processor to isolate the image from its background, and an...