What is Aperture?

The main function of a camera lens is to collect light. The aperture of a lens is the diameter of the lens opening and is usually controlled by an iris.The larger the diameter of the aperture, the more light reaches the film / image sensor. Aperture settings are called f-stops and indicate the size of the aperture opening. Each f-stop lets in half as much light as the next larger opening and twice as much light as the next smaller opening.