Imagine standing on a beach during a beautiful sunset. The colors of the sky paint a mesmerizing scene before your eyes and you’re eager to capture the beauty before you.
As you raise your camera and prepare to take the perfect shot, you realize there’s something off — the exposure isn’t quite right.
How do you fix this?
Well just like an equilateral triangle, the exposure triangle comprises three essential elements that all work in harmony to determine the amount of light that reaches your camera’s sensor — thus affecting the overall exposure of your image.
In this guide, I will demystify the magic behind breathtaking photographs by explaining what the exposure triangle is, and why it’s important.
I will also show you some charts and cheat sheets so you can further understand the exposure triangle and lots more.
Let’s dive in!
What is the Exposure Triangle?
The exposure triangle is a relationship between the three elements that shape the exposure of your image — aperture, shutter speed, and ISO.
In order to understand the basics of the exposure triangle, you have to understand that the exposure triangle is not just about memorizing these three terms, but grasping how the interplay between these three elements affects the overall look of your image.
Each element can be adjusted to achieve your desired creative outcome — whether you want to achieve a normal exposure, or overexposure or underexposure.
Once you understand this, you gain the power to control the exposure in your images and add further creative expression to your images.
The Three Components of the Exposure Triangle
So what are the three elements of the exposure triangle?
Let’s take a closer look at each of these elements and the role each one plays in terms of exposure adjustments.
Aperture refers to the diameter of the lens opening that permits light to reach the camera’s sensor.
It’s measured using a numerical scale, commonly known as “f-stops” such as f/1.4, f/2.8, f/4, f/5.6, f/8, f/16, f/22, and so on.
The wider the aperture, represented by a smaller f-stop number, the more light enters the camera. Conversely, a narrower aperture allows less light to pass through.
When it comes to aperture, each “stop” up or down effectively halves or doubles the size of the opening, consequently affecting the amount of light captured.
For example, moving from f/2.8 to f/4 reduces the opening size by half, resulting in half as much light reaching the sensor.
Apart from regulating the amount of light, aperture also plays a crucial role in controlling the depth of field.
A wider aperture (smaller f-stop) creates a shallow depth of field, where the subject is sharply focused while the background appears beautifully blurred.
On the other hand, a narrower aperture (larger f-stop) extends the depth of field, capturing more elements in sharp focus from foreground to background.
In essence, aperture not only influences the exposure of your image by controlling the amount of light but also allows you to unleash your creativity by manipulating the depth of field and shaping the visual impact of your photographs.
Here is a visual to better understand aperture and f-stops:
It’s a straightforward concept to grasp: a shorter shutter speed means a shorter exposure time, resulting in less light reaching the sensor.
This shorter exposure effectively “freezes” any motion in the scene, capturing fast-moving subjects with sharp clarity.
Here are examples of what I mean by shorter shutter speeds:
- 1/1000s: This speed is commonly used in sports photography to capture athletes in action, freezing their movements mid-stride or mid-jump.
- 1/500s: Ideal for photographing wildlife, this shutter speed allows you to freeze the rapid movements of animals, such as a flying bird or a running cheetah.
- 1/250s: A versatile shutter speed that works well for capturing general action, such as children playing, cars in motion, or people engaged in dynamic activities.
Conversely, a longer shutter speed allows the shutter to remain open for a greater duration, permitting more light to reach the sensor.
This extended exposure time introduces a captivating phenomenon known as “motion blur.”
Moving subjects in the scene appear blurred in the direction of their movement, adding a sense of dynamism and artistic flair to your photographs.
Depending on your artistic vision, motion blur can be a desired effect, enabling you to convey a sense of speed, fluidity, or the passage of time.
Here are examples of what I mean by longer shutter speeds:
- 1/30s: This shutter speed is often used for capturing low-light scenes or indoor photography without a tripod. It can introduce a slight amount of motion blur but still maintains a relatively sharp image.
- 1/15s: A slower shutter speed that can produce noticeable motion blur in subjects with moderate movement, such as people walking or flowing water in a stream.
- 1/8s: This speed is commonly used for intentional motion blur effects, such as capturing light trails from moving vehicles or creating a sense of flowing motion in a waterfall.
- 1/2s: With a half-second exposure, you can capture more pronounced motion blur, like streaks of light in a cityscape or the smooth, silky effect of water in long-exposure landscape photography.
It’s important to note that each increment in the shutter speed setting doubles or halves the exposure time compared to the adjacent setting.
This allows you to precisely control the amount of light that enters the camera and tailor the desired effect based on the scene and your creative intentions.
Mastering shutter speed empowers you to capture crisp, static moments or create captivating blur, giving your photographs a distinct visual impact.
ISO, a crucial element in photography, determines the sensitivity of the camera’s sensor or film to light.
While the concept remains the same between film and digital cameras, in the case of a DSLR, it pertains specifically to the sensor setting.
Understanding ISO allows you to control the exposure of your photographs and adapt to different lighting conditions.
In essence, a lower ISO number indicates lower sensitivity to light, suitable for well-lit environments or when photographing under bright midday sun.
In such situations, opting for the lowest available ISO setting, such as ISO 100 or 200, ensures that your images maintain optimal clarity and minimize the presence of digital noise.
Conversely, in poorly lit scenes or situations where light is limited, higher ISO settings become necessary to compensate for the reduced light.
Increasing the ISO sensitivity, such as ISO 800, 1600, or even higher, allows the camera to capture more light, resulting in properly exposed images.
However, it’s important to note that higher ISO settings often introduce a common challenge—digital noise. This unwanted speckling or spotting can affect the overall quality and sharpness of your images.
It’s worth mentioning that high-end DSLRs generally perform better at handling noise issues at higher ISO settings.
These cameras employ advanced technologies and improved sensor capabilities to mitigate noise problems, allowing for cleaner and more detailed images even at elevated ISO levels.
Understanding ISO sensitivity empowers you to adapt to various lighting conditions, striking a balance between capturing well-exposed images and managing digital noise.
It’s a valuable tool in your photographic arsenal, enabling you to unleash your creativity and achieve desired results in any lighting situation.
Example Exposure Triangle Scenarios
Let’s take a look at some example scenarios so I can show you how each element of the exposure triangle would change in order to capture a well-exposed image.
Please note that these are just example scenarios and not hard-set rules for each setting. I just want to give examples of scenarios I’ve been in:
1. Portrait Photography
Let’s say you’re photographing a portrait session in a well-lit outdoor setting.
To achieve a shallow depth of field and create a pleasing background blur, you set a wide aperture (low f-stop number) like f/2.8.
Since your subject is not in motion, you can opt for a moderate shutter speed, perhaps around 1/125s, to ensure sharpness.
Finally, you adjust your ISO to the lowest setting possible, such as ISO 100, to maintain optimal image quality in ample light.
2. Action or Sports Photography
Let’s say you’re capturing fast-paced sports action on a bright, sunny day.
To freeze the action, you select a high shutter speed, such as 1/1000s, to ensure sharpness and capture the decisive moments.
To maintain a reasonable depth of field, you choose a moderately narrow aperture, like f/5.6.
Since lighting conditions are favorable, you set a low ISO, such as ISO 200, to minimize noise.
3. Night Photography
Let’s say you’re photographing a captivating cityscape at night, where you want to capture the lights and the movement of traffic.
To allow for an extended exposure and capture light trails from passing vehicles, you set a slow shutter speed, such as 10 seconds (you’ll need a tripod for sure).
To ensure a reasonable depth of field, you choose an aperture like f/8.
Due to low-light conditions, you increase the ISO to a higher setting, perhaps ISO 800, to properly expose the scene while managing noise.
4. Landscape Photography
Let’s say you’re exploring a breathtaking landscape during golden hour, with soft, warm light casting a beautiful glow.
To maximize the depth of field and ensure sharpness from foreground to background, you set a narrow aperture like f/16 or even f/22.
Since your subjects are not in motion, you can use a moderate shutter speed, such as 1/60s.
Given the favorable lighting conditions, you select a lower ISO, like ISO 100 or 200, to maintain image quality.
5. Indoor Event Photography
Let’s say you’re capturing candid moments at a dimly lit indoor event.
To avoid motion blur while handheld, you choose a moderately fast shutter speed, such as 1/250s.
Since you want to capture the ambiance of the venue and maintain a reasonable depth of field, you opt for a wider aperture, like f/2.8 or f/4.
To compensate for the low-light conditions, you increase the ISO to a higher setting, such as ISO 1600 or higher, to ensure proper exposure while being mindful of noise.
Why is It Important to Learn About the Exposure Triangle?
Now that you know the basics of the exposure triangle, let’s take a closer look at why it’s important to learn about the exposure triangle.
1. Achieving Proper Exposure
The first and most important reason why you should understand the exposure triangle is to achieve proper exposure.
Understanding how aperture, shutter speed, and ISO sensitivity work together will allow you to control and achieve the proper exposure in your images.
This will ensure your images are neither too bright nor too dark.
2. Creative Control
The second reason it’s important to learn about the exposure triangle is for creative control.
For example, if you want to have a slow shutter speed for a motion blur look, you will need to know how that will affect your ISO and aperture settings.
Since all three elements affect one another, knowing how they all work together will allow you to achieve creative effects such as freeze-frame looks, motion blur looks, bokeh looks, etc.
3. Conveying Emotion and Atmosphere
The third reason it’s important to learn about the exposure triangle is that it will allow you to further convey emotion and atmosphere in your images.
For example, if you use a shallow depth of field with a wider aperture (such as f/1.8) you can blur the background and isolate a subject.
Here’s another example, if you use a faster shutter speed such as 1/1000s you can freeze a moment of action.
Each creative choice you take can add further emotion and atmosphere to your images but you can only make these choices by controlling all three elements of the exposure triangle.
4. Problem-Solving in Challenging Lighting Conditions
The fourth reason it’s important to learn about the exposure triangle is that you will be able to solve problems in challenging lighting conditions.
For example, let’s say you’re in a low-light environment such as a nightclub taking photographs. You will need to bump up your ISO settings but doing this will affect your shutter speed and aperture as well — so knowing how all three elements interact with one another is important.
5. Technical Mastery
The fifth and final reason it’s important to learn about the exposure triangle is that you will gain further confidence as a photographer in your technical abilities.
Just like learning any skill, understanding how your camera operates and how light interacts with the sensor, as well as knowing how to manipulate settings to achieve a desired image will give you confidence.
Exposure Triangle Cheat Sheet
Here is an exposure triangle chart and cheat sheet that I put together for you to better visually understand the exposure triangle.
Save this image to your computer or print it out!
Exposure Triangle Calculators
As photography enthusiasts, we often find ourselves faced with challenging lighting situations that require precise adjustments to the exposure triangle.
Balancing aperture, shutter speed, and ISO sensitivity to achieve the desired exposure can sometimes be a complex task.
This is where exposure triangle calculators come to the rescue, offering a valuable tool for photographers to calculate optimal settings quickly and efficiently.
Here is an exposure triangle calculator that I have used before by Omni.
Exposure Triangle Apps
There are a few apps out there that will help you further understand the exposure triangle.
The ones I recommend include:
- Photo Buddy
- Light Meter
- Assess the Shooting Conditions and Desired Outcome: Begin by evaluating the shooting conditions and determining the desired outcome for your photograph. Consider factors such as available light, subject motion, desired depth of field, and any specific creative effects you wish to achieve. This initial assessment will guide your decision-making process when using the exposure triangle.
- Set the Aperture: Select an appropriate aperture setting based on your creative vision and depth of field requirements. A wider aperture (lower f-stop number) will create a shallower depth of field, ideal for isolating subjects and creating a pleasing background blur. Alternatively, a narrower aperture (higher f-stop number) will increase the depth of field, ensuring sharpness from foreground to background.
- Choose the Shutter Speed: Determine the appropriate shutter speed to control the amount of light entering the camera and capture motion as desired. If freezing fast action is your goal, opt for a faster shutter speed. Alternatively, if you want to introduce motion blur or capture long exposures, select a slower shutter speed. Keep in mind that a longer shutter speed requires stability, such as a tripod, to prevent camera shake.
- Adjust the ISO Sensitivity: Set the ISO sensitivity to match the shooting conditions and desired exposure. In well-lit environments, use a lower ISO value (e.g., ISO 100) to maintain optimal image quality and minimize noise. In low-light situations, increase the ISO (e.g., ISO 800 or higher) to ensure proper exposure while being mindful of potential noise or grain in the image.
- Evaluate the Exposure and Make Adjustments: Capture a test shot and review the exposure on your camera's LCD screen or through the viewfinder. Assess whether the image appears overexposed (too bright) or underexposed (too dark). If needed, make adjustments to the aperture, shutter speed, or ISO sensitivity to achieve the desired exposure. Take additional test shots and repeat this evaluation process until you are satisfied with the final result.
In conclusion, the exposure triangle may seem confusing at first, but once you understand the three elements and how they work together, it becomes easy!
Make sure you take the time to fully grasp each element and you’ll be a master of the exposure triangle in no time!
Frequently Asked Questions
What is the purpose of learning about the exposure triangle?
The purpose of learning about the exposure triangle is to gain control over the exposure of your photographs, allowing you to accurately capture and convey your creative vision. Understanding how aperture, shutter speed, and ISO sensitivity interact empowers you to make informed decisions, adapt to different lighting conditions, and create visually compelling images with the desired depth of field, motion effects, and overall exposure.
What is the most important part of the exposure triangle?
While all three elements of the exposure triangle are crucial, the most important part is subjective and depends on the specific shooting situation and desired creative outcome. However, I believe aperture holds significant importance as it determines the depth of field, controlling the sharpness and isolation of subjects, while also impacting the overall exposure by regulating the amount of light entering the camera.
What does an exposure triangle show you the relationship between?
The exposure triangle shows the relationship between three key elements in photography: aperture, shutter speed, and ISO sensitivity. It demonstrates how adjusting one of these factors affects the other two, allowing photographers to balance and control the exposure of an image while considering variables such as light levels, motion, depth of field, and image noise.
Nate Torres is an entrepreneur, growth marketer, and photographer and writes mostly on those topics. Nate runs his own professional photography business and photography blog called Nate Torres Photography. Nate enjoys learning about new digital marketing strategy and new ways to think creatively. He is also a photography speaker and author on Photofocus.