Aperture, in its most simple meaning, is an opening in the lens. It regulates the amount of light passing onto the film inside the camera, the moment the shutter button is pressed. One can compare Aperture to a hole. The larger the hole the more light that gets in – the smaller the hole the less light gets in.Aperture size is usually calibrated in ‘f-stops’. How often have you seen in your camera settings, something like f/5.6, f/22 etc? Each of these values represents one time the amount of light either more or less in quantity. Moving from one f-stop to the next doubles or halves the size of the amount of opening in your lens and thereby regulating the amount of light getting through it. Any kind of change in your shutter speed, one stop to the next doubles or halves the amount of light that gets in also – this means if you increase one and decrease the other you let the same amount of light in. There is one thing related to Aperture and f numbers is that a smaller f number, such as f/2.8, is in turn a much larger aperture than the bigger f number such as f/22. Confusing right, let me summarize it for you:Large Apertures (in which lots of light gets through) : Small f stop numbers like f/2.8, f/4 etc. Small Apertures (in which less amount of light gets through): Comparatively larger f stop number like f/8, f/22 etc.