Aperture
& Depth of Field
The aperture is the opening of the lens, which means, how much light goes through the lens.
Having a large aperture means more light goes through the lens; used mostly when shooting in low light places. This is because you want to let as much light through the lens as possible when shooting in places where there isn’t much light. Hence, when shooting in places with low light, the f-number should be small which means the aperture is big.
Having a small aperture means less light goes through the lens; this is used mostly during landscape photography as it’s shot outdoors and there’s a lot of light for the camera to capture, which would result in the image being overexposed. Hence, when shooting outdoors, the f-number should be high which means the aperture is small.
The “f-number” is the ratio of the focal length of a camera lens to the diameter of the aperture being used for a particular shot – for example, f8, is indicating that the focal length is eight times the diameter.
Small aperture; causing a large depth of field
Large aperture; causing a shallow depth of field
The aperture also affects the depth of field. The depth of field is how much of the image is in focus.
When you have a small aperture, there is a large depth of field, which means there a lot in focus. This is used mainly during landscape and outdoors photography as you want as much of the landscape as possible.
​
When you have a large aperture, there is a small depth of field. This is used mainly during portraits, close-ups or macro photography.