an optical glass of low dispersion and relatively low refractive index. It is used in the construction of lenses
- Optical density
noun 1. (physics) the former name for reflection density, transmission density optical density n. See absorbance.
noun, Computers, Television. 1. Also, optical disc. Also called laser disk. a grooveless disk on which digital data, as text, music, or pictures, is stored as tiny pits in the surface and is read or replayed by a laser beam scanning the surface. 2. . optical disk or optical disc A plastic-coated disk that stores […]
noun 1. See under . noun, Astronomy. 1. two stars that appear as one if not viewed through a telescope with adequate magnification, such as two stars that are separated by a great distance but are nearly in line with each other and an observer (optical double star) or those that are relatively close together […]
plural noun, Movies, Television. 1. special visual effects, as the wipe or dissolve, created in the camera or especially in a film laboratory by technicians using complex optical and electronic equipment.