what is an aperture on a camera

Aperture refers to the opening inside a camera lens through which light passes to enter the camera and reach the image sensor. It is calibrated in f/stops and is generally written as numbers such as 1.4, 2, 2.8, 4... . The size of the aperture can be adjusted to control the amount of light that enters the camera. A smaller aperture means less light is transmitted through the lens, while a larger aperture means more light is transmitted. Aperture affects exposure and plays a fundamental role in determining the optimal exposure in an image, along with ISO and shutter speed. Aperture also affects depth of field, which is the zone of acceptable sharpness in front of and behind the subject on which the lens is focused. A smaller aperture will give a larger depth of field, while a larger aperture will give a shallower depth of field. Aperture is expressed in f-numbers like f/1.4, f/2, f/2.8 and so on to express the size of the lens opening, which can be controlled through the lens or the camera.