In the most simplistic terms, aperture is the lens’s opening where light is able to enter the camera. It controls the amount of light going in, which allows photographers to achieve different effects with their images.

Aperture is measured in f-numbers, or f-stops. The lower the f-stop, the wider the opening. An aperture of f/16 will create the smallest hole and f/1.4 will create the largest, for example.

Aperture will affect depth of field in a photograph. This is the area of focus in front of and behind the subject that you have focused the lens on. Changing the depth of field will make the area behind your subject look sharper or more out of focus.

• If you use a low f-stop to make the opening larger, you will have less depth of field. This means that your background will be more out of focus.
• If you use a high f-stop to make the opening smaller, you will have more depth of field. This means that your background will be more in focus.

The maximum aperture for your particular lens can be found on the lens itself. Check this when buying a new lens.

Aperture can be used to help you capture images in specific ways. For example, a classic portrait will probably use a low f-stop to give shallow depth perception and make the subject stand out. Experiment and play around with aperture, and you will soon begin to understand how it affects your photography.