Understanding Aperture

Small Depth of Field

Aperture:f/5.6

Shutter Speed:1/100

ISO: 1600

Large Depth of Field

Aperture:f/36

Shutter Speed: .4

ISO: 1600

Aperture is the size of the opening in the lense that permits light to hit the film/digital sensor. It is at the top of the Exposure Triangle, and is what controls how much light is involved in the picture. If you change aperture, shutter speed will be affected. ISO stays consistent. A smaller aperture translates to a smaller lens size, and less light allowed in. This causes a smaller depth of field, which is only able to focus on one section of a scene. In contrast, a larger aperture causes a larger lens, and lets more light in. This results in a larger depth of field, that can focus on an entire scene rather than just an object.