In photography, what is 'aperture'?

Written by Daily Fix - Published 15-Jun-2023, last updated 21-Jun-2024

Aperture is one of the three main exposure controls in photography (sometimes known as the exposure triangle), along with shutter speed and ISO. It refers to the opening in a lens through which light passes to enter the camera. The aperture is measured in f-stops, which is a ratio of the focal length of the lens to the diameter of the aperture opening.

A lower f-stop number (such as f/1.4 or f/2.8) indicates a wider aperture opening, which allows more light to reach the camera sensor. A higher f-stop number (such as f/16 or f/22) indicates a narrower aperture opening, which allows less light to reach the camera sensor.

What impact does aperture have on a photograph?

The aperture is an important tool for photographers to control the look and feel of their images. By adjusting the aperture, photographers can create images with a shallow depth of field to isolate the subject, or with a deep depth of field to capture more of the scene in focus. They can also use the aperture to control the exposure of their images, making them brighter or darker as needed.

So the aperture has two main effects on an image:

Depth of field

Aperture controls the depth of field, which is the range of distances in an image that are in focus. A wider aperture opening (lower f-stop number) will result in a shallower depth of field, with the subject in focus and the background blurred. A narrower aperture opening (higher f-stop number) will result in a deeper depth of field, with more of the image in focus.

Exposure

Aperture also affects the exposure of an image. A wider aperture opening (lower f-stop number) will allow more light to reach the camera sensor, which will result in a brighter image. A narrower aperture opening (higher f-stop number) will allow less light to reach the camera sensor, which will result in a darker image.

How to use aperture in photography

To use aperture in photography, you will need to adjust the aperture setting on your camera. This setting is usually located on the lens or in the camera's menu system. The aperture setting is usually represented by a series of f-stops, such as f/1.4, f/2.8, f/4, f/5.6, f/8, f/11, and f/16.

To change the aperture setting, you will need to turn the aperture ring on your lens, or use the menu system on your camera. The aperture ring will usually have a series of f-stops marked on it, so you can easily see which setting you are currently using.

Once you have changed the aperture setting, you will need to take a test shot to see how it affects the image. You can then adjust the aperture setting as needed until you are happy with the look of the image.

Some tips on using aperture

Here are some tips for using aperture in photography:

Use a wide aperture (lower f-stop number) to create a shallow depth of field, which will isolate the subject and blur the background.

Use a narrow aperture (higher f-stop number) to create a deep depth of field, which will keep more of the scene in focus.

Experiment with different aperture settings to see how they affect the look of your images.

Use the aperture setting to control the exposure of your images.

Conclusion

Aperture is a powerful tool that can be used to control the look and feel of your images. By understanding how aperture works and how to use it, you can create images that are visually stunning and creatively expressive.

Grab your camera and start playing with the aperture settings, it's the best way to learn about this powerful part of the exposure triangle!