Editing Aperture (section)

==In scanning or sampling==
The terms ''scanning aperture'' and ''sampling aperture'' are often used to refer to the opening through which an image is sampled, or scanned, for example in a [[Drum scanner#Drum|Drum scanner]], an [[image sensor]], or a television pickup apparatus. The sampling aperture can be a literal optical aperture, that is, a small opening in space, or it can be a time-domain aperture for [[sampling (signal processing)|sampling]] a signal waveform.

For example, [[film grain]] is quantified as ''graininess'' via a measurement of film density fluctuations as seen through a 0.048&nbsp;mm sampling aperture.