optical negative
81Return loss — In telecommunications, return loss or reflection loss is the loss of signal power resulting from the reflection caused at a discontinuity in a transmission line or optical fiber. This discontinuity can be a mismatch with the terminating load or… …
82Zoom lens — Nikkor 28 200 mm zoom lens, extended to 200 mm at left and collapsed to 28 mm focal length at right A zoom lens is a mechanical assembly of lens elements for which the focal length (and thus angle of view) can be varied, as opposed to a fixed… …
83Video camera tube — In older video cameras, before the mid to late 1980s, a video camera tube or pickup tube was used instead of a charge coupled device (CCD) for converting an optical image into an electrical signal. Several types were in use from the 1930s to the… …
84radiation measurement — ▪ technology Introduction technique for detecting the intensity and characteristics of ionizing radiation, such as alpha, beta, and gamma rays or neutrons, for the purpose of measurement. The term ionizing radiation refers to those… …
85Amino acid — This article is about the class of chemicals. For the structures and properties of the standard proteinogenic amino acids, see Proteinogenic amino acid. The generic structure of an alpha amino acid in its unionized form …
86Image scanner — Desktop scanner, with the lid raised. An object has been laid on the glass, ready for scanning …
87Catadioptric system — A 150 mm aperture catadioptric telescope (Maksutov) A catadioptric optical system is one where refraction and reflection are combined in an optical system, usually via lenses (dioptrics) and curved mirrors (catoptrics). Catadioptric… …
88Curved mirror — Reflections in a spherical convex mirror. The photographer is seen reflected at top right A curved mirror is a mirror with a curved reflective surface, which may be either convex (bulging outward) or concave (bulging inward). Most curved mirrors… …
89Solar sail — Solar sails (also called light sails or photon sails, especially when they use light sources other than the Sun) are a proposed form of spacecraft propulsion using large membrane mirrors. Radiation pressure is about 10 5 Pa at Earth s distance… …
90Widescreen — A widescreen image is a film, computer or television image with a wider and shorter aspect ratio than the standard Academy frame developed during the classical Hollywood cinema era. Silent film was projected at a ratio of four units wide to three …
