a punched-card mounting for microfilmed pages.
- Aperture mask
. a perforated metal plate situated behind the faceplate of a color television picture tube and having holes aligned to insure that each of three electron beams strikes only its corresponding red, green, or blue phosphor dot. noun (television) a perforated metal sheet mounted close to the phosphor-dotted screen in some colour television tubes. The […]
of or relating to a semiautomatic exposure system in which the photographer presets the aperture and the camera selects the shutter speed.
- Aperture ratio
- Aperture synthesis
(in radio astronomy) a technique that combines the inputs of a set of radio telescopes to obtain a greater resolution of images than is possible with a single member of the set. noun an array of radio telescopes used in radio astronomy to simulate a single large-aperture telescope. Some such instruments use movable dishes while […]