Photonics Dictionary: S

Vision by means of retinal rods; vision of the dark-adapted eye. In scotopic vision, the level of luminance is so low that the retinal cones are not stimulated, and there is no color vision.

A television system that uses a slow rate of horizontal scanning to increase its reproduction and transmittance accuracy of printed matter, photographs and illustrations.

In fiber optics, the condition in which each fiber of a bundle carries a separate channel.

A television system in which the images produced appear three-dimensional.

Vision in depth of three dimensions as a result of the spacing of the eyes. This spacing allows the eyes to see objects from slightly different points of view.

A direct-readout television pickup tube.

1. A device used to trace out an object and build up an image. One of the most common of these types is video scanning. The scanning takes place inside the television tube as electrons, guided by...

Also called scanning laser acoustic microscope. A device that uses high-frequency ultrasound waves to penetrate surfaces. A scanning laser beam is used as a detector, which transmits information...

In field-sequential color television, the rotating tricolor disc placed between the subject and the lens, or between the picture tube and the viewer.

With respect to television, the transmission of the signals that originate from variously colored parts of an image in a particular sequential order.

Raster scanning process like that of television: each line is scanned successively.

Short wavelength infrared (SWIR) refers to the portion of the infrared spectrum that encompasses wavelengths roughly between 1,000 and 3,000 nanometers (nm). In the electromagnetic spectrum, infrared...

A lack of resolution in a television image as a result of smear ghosts or an insufficiently high video-frequency response. The distortion appears to be extended horizontally and blurred.

A false image in television that follows the desired image so closely that it appears to be smeared.

The letter form used on visual performance test charts. The overall letter height is equal to five times the thickness of individual strokes. Normal 20/20 vision is represented by the ability to...

Ratio of the radiant flux at a particular wavelength lm to that at any other wavelength l, such that both radiations produce equally intense luminous sensations. The wavelength lm is chosen so that...

An instrument similar to the spectroheliograph, but having a scanning method that is performed by a pair of rapidly oscillating slits or a rotating glass block located before a pair of fixed slits at...

A telescopic light-sensing meter used to measure illumination levels of small regions at a distance of many feet; it is used in professional motion picture and television production to ensure proper...

The perception of depth due to binocular vision.

Supercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the near-infrared or even mid-infrared regions of the electromagnetic...

Abbreviation of "synchronization.'' In television, the timing signals used to drive the scanning process. Horizontal sync triggers the retracing of the raster line beginning at the left-hand...