What is aperture?

Aperture, in a mechanical sense, refers to the size of the opening at the back of the lens, which controls how much light is being passed onto the camera's sensor.

Aperture, often called F-stop, is important to the exposure of your photograph, but it also affects how much of your image is in focus, or the 'depth of field'. This is an important stylistic choice, and impacts the look and feel of your image.

Here are five points to explain and experiment with aperture:

1. Open Wide

When the aperture opening is wide (e.g. a lower value such as f/1.4), the image background appears blurrier and contrasts with the foreground, resulting in a shallow depth of field.

2. Straight and narrow

When the aperture opening is narrow (e.g. a higher value such as f/22), both the background and foreground stay in focus, resulting in a flatness we call deeper depth of field.

3. Striking distance

As you draw closer, or move further from your subject, the depth of field will change. This, combined with your F-stop setting, gives you control of the depth of field in the photograph.