Aperture

Image Processing and Smart Cameras: An aperture is a circular opening within the lens which determines the amount of incident light. A high f-stop number indicates a small aperture, which means that only a small amount of light is allowed to pass into the camera, and the depth of focus is increased. Photoelectronic Sensors: An aperture is a mechanical component positioned in front of the sensor’s emitter or receiver by means of which the diameter of the light beam can be changed.