In optics, the aperture of an optical system (including a system consisted of a single lens) is a hole or an opening that primarily limits light propagated...

Look up aperture in Wiktionary, the free dictionary. The aperture of an optical system is the opening that limits the amount of light that can pass through...

In optics, the numerical aperture (NA) of an optical system is a dimensionless number that characterizes the range of angles over which the system can...

The median aperture (also known as the medial aperture and foramen of Magendie) is an opening of the fourth ventricle at the caudal portion of the roof...

Aperture is a discontinued professional image organizer and editor developed by Apple between 2005 and 2015 for the Mac, as a professional alternative...

relative aperture, because it is the inverse of the relative aperture, defined as the aperture diameter divided by focal length. The relative aperture indicates...

Aperture priority, often abbreviated A or Av (for aperture value) on a camera mode dial, is a mode on some cameras that allows the user to set a specific...

The lateral aperture of the fourth ventricle or foramen of Luschka (after anatomist Hubert von Luschka) is an opening at the lateral extremity of either...

The angular aperture of a lens is the angular size of the lens aperture as seen from the focal point: a = 2 arctan ⁡ ( D / 2 f ) = 2 arctan ⁡ ( D 2 f...

In electromagnetics and antenna theory, the aperture of an antenna is defined as "A surface, near or on an antenna, on which it is convenient to make assumptions...