The Exposure Triangle – Complete Guide for Beginners

Understanding the exposure triangle is a crucial first step for any beginner photographer.

In fact, without understanding the exposure triangle, you’ll never be able to master your exposure settings to have complete creative control over your images.

Well in this guide, I’ll be diving into everything you need to know about the exposure triangle and how to use it to create stunning images.

Don’t let the exposure triangle intimidate you any longer, let’s dive in!

What is the Exposure Triangle?

The exposure triangle refers to the relationship between the three key elements that affect the exposure, or brightness, of your images — aperture, shutter speed, and ISO.

Aperture

Aperture refers to the size of the opening in the lens through which light enters.

A larger aperture (indicated by a smaller f-stop number such as f/1.8) allows more light to enter the camera, resulting in a brighter image with a shallower depth of field. This type of aperture allows for those bokeh effects where you have the subject in sharp focus and the background blurred.

A smaller aperture (indicated by a larger f-stop number such as f/16) allows less light to enter the camera, resulting in a darker image but a narrower depth of field. This type of aperture allows for everyone to be in focus when taking a group photo or capturing everything in focus in a landscape scene.

Shutter Speed

Shutter speed refers to the length of time the camera’s shutter remains open to allow light to enter the camera.

A faster shutter speed such as 1/1000 will allow you to capture stop-action photos and freeze motion. A slower shutter speed on the other hand such as 1/30 will allow you to capture motion blur and create some cool-looking creative effects such as light trails or long-exposure images.

ISO

ISO refers to the camera’s sensitivity to light.

A higher ISO value will allow you to capture images in low-light situations but will introduce more noise or grain into the photo, while a lower ISO value will have no noise or grain but may produce an underexposed image based on your aperture and shutter speed settings.

In summary, understanding how all these three elements work together to affect exposure is essential to creating a well-exposed image.

By adjusting each of these settings, you can control the amount of light that enters the camera and create a certain desired effect in your photos.

Why is it Called the Exposure Triangle?

The three elements and the interdependent relationship between them are called the exposure “triangle,” because just as the sides of a triangle are interconnected, so too are aperture, shutter speed, and ISO.

Changing one of these elements will require adjustments to the other two in order to maintain the desired exposure. Here are a couple of examples although we’ll be covering more in-depth later in this guide.

For example, if you increase the aperture size to let in more light, you will need to either increase the shutter speed or decrease the ISO to maintain the correct exposure.

Similarly, if you want to capture a moving subject with a fast shutter speed, you may need to increase the ISO to compensate for the reduced amount of light entering the camera.

Who Invented the Exposure Triangle?

While there is no single inventor or originator of the term, the exposure triangle has been used by photographers for decades.

In the early days of photography, cameras were often large and bulky and the process of taking a photo required a great deal of skill and knowledge.

Photographers had to carefully control the exposure of their images using methods such as adjusting the aperture size and the duration of the exposure. However, it wasn’t until the advent of modern cameras and film that the exposure triangle as we know it today began to take shape.

With the introduction of automatic exposure modes in cameras, many photographers became reliant on the camera’s metering system to determine the exposure.

However, experienced photographers knew that manual control over the exposure triangle was essential to creating well-exposed photos and achieving creative effects.

Today, the exposure triangle remains a fundamental concept for photographers of all levels. It allows photographers such as yourself to take full control over the exposure of their photos and create a range of effects and styles. While the origins of the exposure triangle may be difficult to trace, its importance to the art of photography is undeniable.

How do You Use the Exposure Triangle?

In order to use the exposure triangle effectively, you must understand how each element individually affects the exposure of your photos.

Once you have a grasp of aperture, shutter speed, and ISO, you can adjust each setting to achieve the desired exposure and creative effect.

Here are some steps I use that will better help you use the exposure triangle:

1. Start With Your Aperture

In order to use the exposure triangle, the first step is to start with your aperture settings.

Aperture is one of the key elements of the exposure triangle and has a significant impact on the depth of field in your photos.

I always start with the aperture first so I can control the depth of field as that is the first creative choice I always enter a scene with.

When you choose a wider aperture (lower f-stop number), you allow more light to enter the lens which will create a shallower depth of field.

A shallow depth of field is great for portraits, headshots, or product images as they will allow you to isolate the subject and create a soft, blurred background — great for drawing emphasis to your subject.

On the other hand, a narrower aperture (higher f-stop number), will reduce the amount of light entering the lens, creating a larger depth of field.

This means that more of the image will be in focus which is ideal for landscapes, street photography, or architectural photography as you will be able to capture sharp detail throughout the image — from the closest object to the horizon.

It’s important to note that choosing the right aperture is not just about creating a desired depth of field. It also affects the amount of light entering the camera, which is an essential consideration when choosing the other elements of the exposure triangle.

For example, if you choose a wider aperture, you will need to increase the shutter speed or decrease the ISO to compensate for the increased amount of light entering the camera — this leads us to my next tips.

2. Set the Shutter Speed

The second step is to then set your shutter speed which will determine the length of time that your camera’s shutter will remain open when capturing an image.

The shutter speed is measured in fractions of a second and is responsible for controlling motion blur and freezing action in your photos.

So essentially, you need to ask yourself — do you want to capture and freeze frame your image like in stop-action photography or do you want to have an image with motion blur.

A faster shutter speed will freeze fast-moving subjects, such as athletes or wildlife. For example, in sports photography, a shutter speed of at least 1/500th of a second is often required to freeze the action and capture an athlete in motion.

On the other hand, a slower shutter speed is perfect for creating a motion blur effect to your images. This is often used creatively when you want to capture a long exposure image such as with the movement of an element such as a waterfall or cars driving down the highway.

It’s important to note that using a slower shutter speed requires a steady hand or tripod to avoid camera shake and ensure a sharp image.

Additionally, if you are using a slower shutter speed, you may need to compensate for the increased amount of light entering the camera by choosing a narrower aperture or lower ISO.

3. Set the ISO

Once you know what depth of field you want with your aperture settings and whether or not you want to freeze the frame in your image with shutter speed, it’s time to set the ISO.

ISO determines the sensitivity of the camera’s image sensor to light and is measured in number values — with higher numbers indicating higher sensitivity to light and vice versa.

In low-light conditions, such as indoors or at night, a higher ISO is necessary to capture enough light and avoid underexposure. Using a higher ISO, however, can result in more digital noise or grain in the photo, reducing the image’s overall quality.

In bright conditions, using a lower ISO is recommended to produce a cleaner image with less noise. This is because, with more light available, your camera’s image sensor does not need to be as sensitive to light, resulting in a higher-quality image.

In summary, choosing the appropriate ISO depends on the lighting conditions and the desired effect, with a higher ISO ideal for low-light situations and a lower ISO perfect for bright conditions. However, it’s essential to be aware of the impact of ISO on the image’s overall quality and consider the other elements of the exposure triangle to achieve the desired exposure.

Examples of Using the Exposure Triangle

Now that we’ve covered the steps in order to use the exposure triangle, let’s take a look at some examples of how to use the exposure triangle to achieve different effects and create stunning images.

1. Shallow Depth of Field Portraits

If you want to capture a portrait photo with a blurred background, start by selecting your aperture and choosing a wide aperture (low f-stop number).

A wider aperture creates a shallow depth of field which will blur the background and keep your subject in focus.

From there, you will want to choose a high enough shutter speed to keep them in focus without motion blur and an ISO to achieve the correct exposure, ensuring the subject is properly exposed.

2. Motion Blur

If you want to create motion blur in your images, start by setting a slow shutter speed.

The longer the shutter is open, the more motion blur will be created in the image. This technique works well for capturing the movement of water, traffic, or people.

You can then adjust the aperture and ISO to achieve the correct exposure and ensure that the image is not overexposed.

3. Vast Landscapes in Focus

For landscape photography, it’s best to use a smaller aperture (higher f-number) to achieve a larger depth of field, ensuring that both the foreground and background are in focus.

You may need to use a slower shutter speed to achieve the correct exposure, but a tripod can help you stabilize the camera and avoid camera shake.

A lower ISO is also recommended to produce a cleaner image with less noise.

4. Stop Action Photography

If you want to capture a stop action photograph, it requires a fast shutter speed to freeze motion and capture fast-moving subjects.

You can use a wider aperture (lower f-number) to achieve a shallower depth of field and isolate the subject.

A higher ISO may be necessary to achieve the correct exposure, but be aware of the potential noise or grain in the final image.

5. Night Photography

Shooting at night can be challenging, but by using a wider aperture, a longer shutter speed, and a higher ISO, you can capture stunning images of the night sky or cityscapes.

A tripod is essential to avoid camera shake, and using a remote shutter release can help you avoid touching the camera and causing vibrations.

All-in-all, these are just a few examples of how to use the exposure triangle to achieve different effects and create stunning photos.

With practice and experimentation, you can develop your own style and master the exposure triangle, giving you greater control over your images’ final look and feel.

Common Mistakes to Avoid With the Exposure Triangle

While the exposure triangle and mastering its key elements is crucial to capturing stunning photos that you have creative control over — it can also be a source of frustration and disappointment if not used correctly.

Let’s take a look at some common mistakes to avoid, mistakes that I’ve also made at one point or another that you can learn from.

1. Overexposure or Underexposure

One of the most common mistakes with the exposure triangle is overexposing or underexposing the image.

Overexposure occurs when there is too much light in the image, resulting in a bright and washed-out look.

Underexposure occurs when there is not enough light in the image, resulting in a dark and muddy look.

To avoid these mistakes, pay attention to the camera’s light meter and adjust the aperture, shutter speed, and ISO accordingly.

2. Not Paying Attention to Depth of Field

The second mistake is not paying attention to depth of field.

The depth of field can greatly impact the final look of the image. If you’re not paying attention to the depth of field, you may end up with a blurry background or foreground when you wanted everything in focus, or vice versa.

Make sure to choose the appropriate aperture size based on the depth of field you want to achieve.

3. Ignoring the Shutter Speed

The third mistake is ignoring the shutter speed.

Shutter speed is an important component of the exposure triangle, and it can greatly affect the final look of the image.

If you’re not paying attention to the shutter speed, you may end up with blurry or shaky images. Make sure to choose the appropriate shutter speed based on the subject and the effect you want to create.

4. Not Considering the ISO

The fourth mistake is not considering the ISO.

ISO is an important component of the exposure triangle, especially in low-light conditions. If you’re not considering the ISO, you may end up with images that are too noisy or grainy.

Make sure to choose the appropriate ISO based on the lighting conditions and adjust the aperture and shutter speed accordingly.

5. Not Using a Tripod

The fifth and final mistake is not using a tripod.

Using a tripod can greatly improve the final look of your images, especially when using slower shutter speeds or smaller apertures.

Not using a tripod can result in blurry or shaky images, even if the exposure settings are correct.

Final Thoughts

In conclusion, mastering the exposure triangle is a fundamental step toward taking better photos. Understanding how aperture, shutter speed, and ISO work together to control the exposure of an image can open up endless possibilities for creative expression. With practice and experimentation, you can learn to use the exposure triangle to achieve the desired look and feel for your photos.

Remember, the exposure triangle is not a set of strict rules, but rather a guide to help you achieve your vision for your photos. Don’t be afraid to break the rules and experiment with different settings to create unique and stunning images.

By starting with the basics and practicing with different scenarios, you can become more comfortable with using the exposure triangle and taking better photos. So grab your camera, get out there, and start exploring the world of photography with the exposure triangle as your guide.

Frequently Asked Questions

Additional Resources

Be sure to also read these articles related to photography exposure:

• The Exposure Triangle – Complete Guide for Beginners
• What is ISO in Photography? Complete Guide for Beginners
• Shutter Speed in Photography
• What is Aperture in Photography? The Beginner’s Guide