Aperture, Shutter Speed & ISO Explained

by Ceenan Calzadilla

Aperture

Aperture can be defined as the opening in a lens through which light passes to enter the camera. It can add dimension to your photos by controlling depth of field. Depth-of-field is the zone of sharp focus in a scene, and this can be controlled by the aperture settings.

A small number like f1.8 to f5.6 is referred to as shallow depth-of-field, great for uncluttering the background and making your subject stand out. A larger number like from f8 to f22 is referred to as a large depth-of-field, normally ideal for landscapes as it keeps both the foreground and background in focus.

Use this slide bar to see how a wide-open aperture (small number) compares to a narrow aperture opening (large number).

Shutter Speed

Shutter speed refers to the amount of time that the camera's shutter is open. The longer it is open, the more light passes through to the camera's sensor.

Slower shutter speeds like 1/4 second will capture motion and cause a blurring affect in a moving subject.

Using a faster shutter speed like 1/250 or higher will capturing fast-moving subjects with minimal or no motion blur.

Use this slider to see how different shutter speeds affect the image.

ISO

In digital photography, ISO measures the sensitivity of the image sensor. The lower the number, the less sensitive your camera is to light.

Higher numbers mean your sensor is more sensitive to light, and this allows you to use your camera in darker situations.

However, raising your ISO has consequences. A photo taken at too high of an ISO will show a lot of grain, also known as noise.

Use this slider to see how ISO affects an image taken at dusk.