1.The iris of the digital camera which is a circular opening within the lens that opens and closes to permit varying levels of light to enter the camera as the image is exposed in order to record the digital image. The maximum aperture determines how much a lens can be open such as f/1.8 which lets in considerably more light than f/3.2 which opens only slightly. A “wide open iris” is considered to be a large or high aperture setting.
2.Lens opening. The opening in a camera lens through which light passes to expose the film. The size of aperture is either fixed or adjustable. Aperture size is usually calibrated in f-numbers-the larger the number, the smaller the lens opening.