Understanding The Exposure Triangle

Words by Scott Bourne - A Platypod Pro
Edited by Eryka Bagwell



The exposure triangle is a fundamental concept in photography that refers to the relationship between three critical elements in determining the exposure of a photograph. These elements are aperture, shutter speed, and ISO, and they work together to control the amount of light that enters the camera.

Understanding the exposure triangle is essential for achieving proper exposure, creating specific effects, and producing high-quality images. In this blog post, we will discuss each element of the exposure triangle in detail.

But let's start with the concept. Think of exposure as a table with three legs. When all three are accounted for, it’s possible to have a properly balanced table. The same holds true for photography, all three must be balanced if you want a proper exposure.

Now to the specifics of each part of the exposure triangle...

Aperture:
The aperture is the opening in the lens through which light passes into the camera. It is measured in f-stops, which represent the ratio of the lens's focal length to the diameter of the aperture. A lower f-stop number, such as f/1.8 or f/2.8, indicates a larger aperture opening, which allows more light to enter the camera. In contrast, a higher f-stop number, such as f/16 or f/22, indicates a smaller aperture opening, which lets less light into the camera.

The aperture not only controls the amount of light entering the camera but also affects the depth of field in the image. A larger aperture opening (lower f-stop) results in a shallow depth of field, meaning that only a small portion of the image is in focus while the rest is blurred. This effect is useful for portraits or macro photography, where the subject needs to be isolated from the background.

On the other hand, a smaller aperture opening (higher f-stop) results in a deeper depth of field, meaning that more of the image is in focus. This effect is useful for landscapes, architectural photography, and other situations where sharpness throughout the image is essential.

Shutter Speed:
The shutter speed refers to the amount of time the camera's shutter remains open when taking a photograph. It is measured in seconds or fractions of a second, such as 1/500 or 1/30. A faster shutter speed, such as 1/1000 or 1/2000, means that the shutter remains open for a shorter period, allowing less light into the camera. In contrast, a slower shutter speed, such as 1/30 or 1/2, means that the shutter remains open for a longer time, allowing more light into the camera.

The shutter speed not only controls the amount of light entering the camera but also affects the motion in the image. A faster shutter speed freezes motion, while a slower shutter speed creates motion blur. This effect is useful for sports or action photography, where freezing the subject's motion is crucial. In contrast, a slower shutter speed is useful for creating artistic effects, such as smooth waterfalls or light trails.

ISO:
ISO refers to the camera's sensitivity to light, and it is measured in numbers such as ISO 100, ISO 200, ISO 400, and so on. A lower ISO number means that the camera is less sensitive to light, while a higher ISO number means that the camera is more sensitive to light.

Increasing the ISO allows the camera to capture more light in low-light situations, but it also introduces noise or grain into the image. Therefore, it is essential to use the lowest ISO possible to achieve the desired exposure and avoid noise.

Exposure Triangle Application:
Now that we have discussed each element of the exposure triangle let's look at an example of how they work together to create a photograph.



Mountain Lion Jumping:
The most important part of this example image is freezing the action when the big cat jumped between the two rocks. Shutter speed priority was used to freeze the action, aperture was stopped down to provide depth of field, and a high ISO allowed fast shutter speed.

Depending on what's important to you in your next photograph, you can use the exposure triangle to accentuate the part of the image that matters most.

Visit the Platypod store to check out all the new sales to boost your creativity. Click Here  

If you have a final image and BTS that you’d like to share and potentially be featured on our blog (newsletter or social media pages), please contact us via service@platypod.com.