Aperture

• in photography, aperture refers to the diameter of the aperture stop, a device called a diaphragm acts as the aperture stop in a camera, and controls the effective diameter of the lens opening.
• The aperture stop can be adjusted to control the amount of light reaching the film or image sensor.
• works in combination with shutter speed. Typically a fast shutter speed requires a larger aperture to ensure sufficient light exposure. Whereas a slow shutter speed will require a smaller aperture to avoid excessive exposure.
• The lens aperture is usually specified as an f-number. A lower f-number denotes a greater aperture opening which allows more light to reach the film or image sensor.