Aperture and shutter speed

What is Aperture?

Put most simply – Aperture is ‘the opening in the lens.’

When you hit the shutter release button of your camera a hole opens up that allows your cameras image sensor to catch a glimpse of the scene you’re wanting to capture. The aperture that you set impacts the size of that hole. The larger the hole the more light that gets in – the smaller the hole the less light.

Aperture is measured in ‘f-stops’. You’ll often see them referred to here at Digital Photography School as f/number – for example f/2.8, f/4, f/5.6,f/8,f/22 etc. It can mean the difference between one dimensional and multi dimensional shots.

Depth of Field (DOF) is that amount of your shot that will be in focus. Large depth of field means that most of your image will be in focus whether it’s close to your camera or far away.

     

These images have a small depth of field (DOF)

      

These images have a large depth of field (DOF)

Depth of field examples using F numbers:

Nikon Digital SLR - D40/D50/D3000

  The mode dial is the small circular knob on the top right of the camera on this picture this controls the aperture priority, the circular dial beneath the mode dial to the right is the main command dial; this changes your aperture when using aperture priority.

The F number and shutter speed are displayed on the camera's digital screen, for example the F number on this camera is f 5.6 and the shutter speed is 1.