“You say aperture, I say…you lost me.” Many people trying to learn how to use an SLR camera can comprehend the shutter speed, and have heard of ISO, but when aperture is added to the pile, all hope is lost. Well don’t sweat it, because aperture is actually one of the easiest settings to understand when its explained in the right way!!
The best way to understand one part of aperture is to compare it to a faucet. Just like the shutter speed and ISO, the aperture controls how much light is allowed into the camera’s lens, similar to how a faucet can control how much water is allowed to pour out. The ‘wider’ the aperture (lower the f-stop number) the more light is allowed in, and consequently the brighter the picture will be. The ‘narrower’ the aperture-or tighter you screw the faucet, the less light and water will be allowed through.
Aperture also affects the depth of field. A shallow depth of field is achieved with a lower f-stop number and creates an out of focus foreground and background. A deeper depth of field is achieve with higher f-stop numbers and creates an images where both near and far are in focus.