You’re neglecting a crucial aspect of photography if you have yet to grasp the Exposure Triangle. This is not just a camera setting or technique but a fundamental concept. Yet, it’s often overlooked as it appears quite complex.

The good news is that it’s not nearly as difficult as it first seems. But more importantly, understanding what the Exposure Triangle is and how it works is an essential part of becoming a better photographer.

To fully take advantage of your equipment, you must comprehend how the camera settings affect each other. Once you master that, you will quickly see a notable difference in your photography.

The Exposure Triangle is part of the fundamentals of photography. In this article, you’ll learn what it is and why you will benefit from understanding it.

Let’s dive right into it:

What is the Exposure Triangle?

The Exposure Triangle is a fundamental concept in photography that refers to the relationship between three key settings: aperture, shutter speed, and ISO. These three factors work together to control a photograph’s exposure.

The Exposure Triangle Infographic

Exposure is one of the most critical aspects of creating a good image, as it refers to the amount of light that reaches the camera’s sensor. In other words, it determines how bright or dark your photo is.

The three elements of the Exposure Triangle need to be balanced to get a correctly exposed image. This means that changing one of the settings will impact the brightness, and you’ll need to correct it by adjusting one of the others too.

I will return to specific Exposure Triangle examples at the end of this article to show precisely how it works.

What are the Exposure Triangle Camera Settings?

Chances are that you’re already familiar with the Shutter Speed, Aperture, and ISO. Whether you are using auto or manual mode when taking pictures, it’s these settings that are adjusted.

To understand how the Exposure Triangle works, you don’t only need to understand these settings, but you also need to understand the relationship between them. What happens when you change the Shutter Speed? What happens when you increase the ISO?

Understanding the Exposure Triangle is essential to becoming a good photographer, and you should learn it early on. Let’s start by taking a look at the three fundamental camera settings before looking at the relation between them:

#1 Aperture in the Exposure Triangle

The first camera setting in the Exposure Triangle is the Aperture.

This setting refers to the opening in which light enters through your camera’s lens and is measured in f-stops, such as f/2.8, f/4, f/5.6, or f/22.

Aperture in the Exposure Triangle

A lower f-stop number (such as f/2.8) corresponds to a larger opening, allowing more light to enter the camera. A higher number (such as f/22) corresponds to a smaller opening, allowing less light to enter the camera.

Aperture also affects the Depth of Field, which is the range of sharpness in a photograph. A wider aperture (lower f-stop) results in a shallower Depth of Field. In comparison, a narrower aperture (higher f-stop) increases it.

Again, we see that there are multiple factors to consider when adjusting a setting of the Exposure Triangle. A change in aperture will affect a photo’s exposure and sharpness.

Read our Introduction to Aperture in Landscape Photography to learn more about this important camera setting.

#2 Shutter Speed in the Exposure Triangle

Shutter Speed is the second component of the Exposure Triangle. This camera setting refers to the duration of time that the camera’s shutter is open. In other words, allowing light to reach the sensor and create a photograph. This period is measured in seconds or fractions of seconds.

For example, a large denominator such as 1/2000 is a quick Shutter Speed. The camera’s sensor is exposed to light for only a fraction of a second, meaning less light is let through. This is commonly used when photographing in broad daylight or when photographing quickly moving elements (such as freezing a bird in flight)

A slower Shutter Speed, such as 1/4th of a second, means the sensor is exposed to light for longer. This is common when photographing in dimmed light or when wanting to blur moving objects. Long Exposure Photography is a popular technique that takes advantage of the fact that the camera registers all movements while the shutter is open.

The longer the Shutter Speed, the more light the camera will capture, and vice versa.

Shutter Speed in the Exposure Triangle

A vital factor to consider about the Shutter Speed and the Exposure Triangle is that a longer exposure time means the camera registers more motion. Whether it’s from camera vibration or a moving element within the frame, it will show in the final image. That is why you can’t simply use a longer Shutter Speed to make a brighter exposure without taking the proper precautions (such as using a tripod)

Read our Introduction to Shutter Speed in Photography to learn about this creative camera setting.

#3 ISO in the Exposure Triangle

The third side of the Exposure Triangle refers to the ISO. This camera setting represents the camera’s sensitivity to light.

It is measured using numbers such as ISO100, ISO200, ISO400, ISO1600, etc.

A lower ISO number indicates less sensitivity to light, requiring more light to achieve a proper exposure. Higher ISO numbers amplify the sensor’s sensitivity, allowing for better exposures in low-light conditions.

As you’ve learned by now, there’s always another factor to consider. While a higher ISO makes the camera more light-sensitive, it also introduces digital noise or grain to the photo. The higher the ISO, the more noise becomes visible.

ISO in the exposure triangle

The exact value at which noise becomes problematic will depend on the camera that you’re using. Typically, professional cameras handle noise significantly better than entry-level models.

Read More: An Introduction to ISO in Digital Photography

How the Exposure Triangle Works – Connecting the Settings

So how exactly does the Exposure Triangle work? How are these camera settings impacting each other?

Let’s get visual for a second as I explain this in the simplest way I know.

Imagine that you want to fill a room with water. There’s a window on the wall where water enters. To let water in through the window, you need to open it. The more you open the window, the more water comes in. This resembles the aperture.

The longer you keep the window open, the more water enters the room, and vice versa. This resembles the shutter speed. Now let’s connect the two and see how they rely on each other; If there’s just a tiny opening in the window, it will take longer to fill the entire room with water. If you open the window to the widest, it will go much faster.

In photography terms, that means that the wider aperture you have (such as f/2.8), the quicker shutter speed you need to get a correctly exposed image.

Exposure Triangle Explained

So what about the ISO? Let’s stick to the same scenario and pretend there’s a lot of dirt in the water you’re letting in. You get rid of this dirt by installing a filter inside the window. A filter with tiny holes removes all the dirt from the water; this resembles a low ISO, such as 100. However, since the holes are so small, water enters slower. This means you need to leave the window open for longer (i.e. slower shutter speed) or open it wider (large aperture).

A filter with big holes lets water come through quicker but reduces water quality.

In photography, a higher ISO results in more grain, noise, and overall lower image quality.

What to Consider When Adjusting Camera Settings

The example above is an easy way to explain the Exposure Triangle. However, it doesn’t consider the two elements we briefly looked at earlier; motion and Depth of Field. You see, changing the camera settings doesn’t come without consequences.

Let’s say that your image is two stops underexposed (one stop means doubling or halving the light in a photo), and you choose to use a slower shutter speed, for example, 1/10th of a second, to get a good exposure. 

Doing so will fix the exposure problem, but most likely, your image is now a little blurry. This is because a longer exposure time means the camera registers more motion. If you’re taking a handheld photo, you need to consider how long you can keep the camera steady. 

On the other hand, using a wider aperture (for example, f/2.8 instead of f/5.6), you will most likely find either your foreground or background out of focus. This is due to the shallow depth of field you get with such a wide aperture.

So how do you know what camera settings to adjust? Unfortunately, there’s no definite answer to this. It depends on the situation.

Handheld Telezoom Photography
Every scenario has different criteria. In this case, I needed a quick shutter speed to avoid camera shaking and to freeze the bird.

That being said, here’s a rule of thumb that I often operate by:

  • ISO remains as low as possible
  • Aperture between f/7.1 and f/13
  • Shutter speed quicker than 1/60th of a second when photographing handheld*
  • Shutter speeds slower than 1/60th of a second require the use of a tripod*
  • If the image is too dark when using f/7.1 and 1/60th of a second, and I don’t have a tripod, I will increase the ISO

 * The slowest shutter speed depends on the lens you’re using. You can get away with slower shutter speeds when using ultra-wide-angle lenses compared to tele-zoom lenses. A rule of thumb is never to go below 1/focal length when photographing handheld. That being said, Image Stabilization is rapidly improving, so trial and error is the best way to know your equipment.

Why is the Exposure Triangle Important?

So why is it so important to understand the Exposure Triangle? I think you’ve already got an idea if you’ve made it this far.

The Exposure Triangle represents the relationship between the three fundamental camera settings controlling exposure in your images. A well-exposed image is an essential part of becoming a better photographer.

By understanding how these settings work in unison, you can make better and more qualified decisions in the field. You no longer need to rely on an automatic mode (which values technicality over creativity) but instead take complete control over the image-making process.

This is why every photographer needs to understand the Exposure Triangle.

What is the Most Important Setting in the Exposure Triangle?

There’s no blueprint for which setting in the Exposure Triangle you should change first or which is the most important. As mentioned before, it all depends on the situation.

Different genres of photography have other priorities, and within that genre, many factors need to be considered depending on what you’re photographing.

Let’s take a look at a few example situations:

  • When photographing a grand landscape, you typically want an aperture between f/7.1 and f/13, as this gives you the best front-to-back sharpness. The ISO should remain as low as possible to minimize the amount of noise, which means you should adjust the shutter speed to get a perfect exposure. Add wind to the equation, and you might need to increase the ISO instead to avoid blurring any moving elements within the frame.
  • When photographing birds in flight, you need a quick shutter speed, such as 1/4000th of a second. In this case, you can achieve that by using a wide aperture such as f/2.8 and increasing the ISO until the Exposure Triangle is balanced.
  • Night photography requires a wide aperture, slow shutter speed, and high ISO. Here, the ISO is often adjusted as the two other components should be more fixed.

As you can see, there isn’t a most important setting in the Exposure Triangle. They all play equally important roles in creating a well-exposed image.

Understanding Exposure Stops

You might have picked up on the term Exposure Stops a few times in this article, so I’ll quickly explain what this refers to.

Simply put, an Exposure Stop refers to the doubling or halving of light that reaches the sensor. Those familiar with Neutral Density filters will know that a 6-Stop filter allows six stops less light to reach the camera sensor. In other words, it halves the amount of light by six times (a 1-second shutter speed will now be 64 seconds)

Stops are an important factor in balancing the Exposure Triangle. When you adjust one side, you’ll need to compensate on one of the other. Suppose you change the aperture with one stop (going from f/4 to f/2.8 doubles the amount of light). In that case, you need to compensate for one stop by either using a quicker shutter speed or a lower ISO.

Exposure Stops Chart
A chart showing the difference between one Exposure Stop

Do You Need a Perfectly Balanced Exposure Triangle?

Now that you know how to use the Exposure Triangle in your photography, the big question is, do you need to get the “perfect” exposure every time you take a photo? Do you always need to compensate when adjusting one of the camera settings?

No. Achieving a technically perfect image isn’t always realistic. Sometimes you need to react to the moment and won’t have time to calculate compensations.

This is one of the most significant advantages of digital cameras. You’re able to make substantial changes to the exposure in post-processing. In other words, if your image is a little underexposed, correcting it in photo editing software such as Adobe Lightroom or Adobe Photoshop is relatively easy.

Does that mean it’s ok to slack when using the Exposure Triangle? No. You should always be aware of what you’re doing. There are certain guidelines you should follow when it comes to applying the best settings. Failing to do so can severely damage the image quality.

Conclusion

Understanding how the camera settings are connected can be confusing in the beginning, but I hope this Exposure Triangle guide made it a little clearer.

The Exposure Triangle is a term that describes how the three camera settings, shutter speed, aperture, and ISO, all have an impact on the exposure of an image. Changing one setting has a direct impact on the others.

Using a high ISO makes it possible to use a quicker shutter speed or smaller aperture but at the expense of the image quality. Reducing the ISO means you need to use a wider aperture or slower shutter speed.

There are a few more factors to consider when adjusting the Exposure Triangle, but neither of these impacts the image’s exposure. For example, a slower shutter speed means you probably need to use a tripod in order to get a sharp image. The choice of aperture affects the Depth of Field and focus of the image.

But, for now, grab your camera and set it to manual mode, and play around with these three camera settings. Try to notice how adjusting one or the other affects the exposure and quality of the image.

Got any questions? Let me know in the comments, and I’ll do my best to help!


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