E - Exposure Triangle: Balancing Light
The exposure triangle is a fundamental concept that every photographer should master.
(Image Credit: Sylwia Bartyzel)
Photography is all about capturing light, and understanding how to control that light is crucial for creating well-exposed images. The exposure triangle is a fundamental concept that every photographer must master. It refers to the relationship between three key elements: aperture, shutter speed, and ISO. These three components work together to control the amount of light reaching the camera film / sensor and determine the overall exposure of your image.
Every camera has an aperture. Most cameras allow for adjustable aperture settings, while some, like most smartphones, have a fixed aperture.
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Aperture: Controlling Depth and Light
Aperture is the opening in your camera lens that controls how much light enters the camera. It is measured in f-stops (e.g., f/2.8, f/5.6, f/11), and it plays a dual role in determining exposure and depth of field. The f-stop value determines the size of the aperture opening: a lower f-stop number (e.g., f/2.8) indicates a wider opening, while a higher f-stop number (e.g., f/16) indicates a smaller opening.
A large aperture can capture more light in dim environments, thus reducing the shutter speed required.
(Image Credit: Juliane Liebermann)
A wider aperture (e.g., f/2.8) allows more light to reach the sensor, making it ideal for low-light situations like indoor events or nighttime photography. At the same time, a wide aperture results in a shallow depth of field, which is perfect for isolating a subject by creating a beautiful blurred background, commonly seen in portrait photography. This effect, known as bokeh, adds a professional touch to images by drawing attention to the subject and softening distracting background elements.
Another advantage of a large aperture is that it creates a blurred background effect.
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On the other hand, a smaller aperture (e.g., f/16) restricts the amount of light entering the camera, which is useful for bright environments like a sunny day outdoors. A smaller aperture also increases the depth of field, keeping more of the scene in focus from foreground to background. This is ideal for landscape photography, where it’s important to capture intricate details across the entire frame. Using a smaller aperture ensures that every element, from nearby rocks to distant mountains, remains sharp and clear.
A small aperture (e.g., f/11) maintains a larger depth of field, which is especially useful in landscape photography.
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Shutter Speed: Freezing or Blurring Motion
Shutter speed refers to how long the camera’s shutter remains open, allowing light to hit the sensor. Shutter speed is measured in seconds or fractions of a second (e.g., 1/1000s, 1/30s, 5s). It has a direct impact on how motion is captured in your photos, influencing whether moving subjects appear frozen or blurred.
For bird photography, a fast shutter speed — usually shorter than 1/1600s — is ideal.
(Image Credit: Anna Storsul)
A fast shutter speed (e.g., 1/1000s) is used to freeze motion, making it ideal for action photography, such as sports, wildlife, or children playing, where capturing sharp images of moving subjects is important. By using a fast shutter speed, you can eliminate motion blur, ensuring that every detail is crisp and well-defined. This is particularly useful when photographing unpredictable subjects, such as birds in flight or athletes in mid-action.
In sports photography, a shutter speed faster than 1/1600s is preferable to freeze motion and achieve a sharp image.
(Image Credit: Matthieu Pétiard)
Conversely, a slow shutter speed (e.g., 1/30s or longer) allows more light to enter the camera and can be used to create a sense of motion. This is often used in creative photography, such as capturing light trails from cars at night or to create a smooth, silky effect on flowing water in landscape photography. Slow shutter speeds can convey movement, adding an artistic touch to images that tell a story. For example, capturing the motion of waves crashing on the shore or the movement of clouds across the sky can evoke a sense of time and fluidity.
For a silky effect in waterfall photography, use a long exposure (typically more than 1 second) and a tripod to prevent camera shake.
(Image Credit: John Rodenn Castillo)
ISO: Sensitivity to Light
ISO refers to the sensitivity of your camera's sensor to light. Lower ISO values (e.g., ISO 100) are less sensitive to light, producing cleaner images with minimal noise. This is ideal for shooting in bright conditions or when you want the highest possible image quality. Lower ISO values are often used in studio photography or on bright, sunny days when there is plenty of available light.
Many digital cameras allow ISO adjustments for better control over exposure in varying lighting conditions. Do you know how we adjust this setting in the film era?
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Higher ISO values (e.g., ISO 1600, ISO 3200, or higher) increase the sensor’s sensitivity, allowing you to shoot in low-light conditions without needing to slow down the shutter speed or open the aperture further. This can be extremely helpful when shooting indoors, during concerts, or in other dimly lit environments where using a flash may not be practical or desirable.
Concert photography often requires a high ISO setting, around 800-1600, to compensate for low light.
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ISO also plays a creative role in determining the mood of your image. For example, using a higher ISO can add a gritty, textured feel to black-and-white street photography, whereas a lower ISO is ideal for creating smooth, polished images with vivid colors. Understanding how to balance ISO with aperture and shutter speed is key to minimizing noise while maintaining the desired depth of field and sharpness.
High ISO (e.g., 3200) can be used to add grain and texture to black-and-white photography for a creative effect.
(Image Credit: Shifaaz Shamoon)
Automatic Exposure and Its Limitations
In addition to manual control, many modern cameras (including smartphones) offer automatic exposure, where the camera's metering system determines the "correct" exposure for the scene. This is a convenient feature, especially for beginners, as it allows the camera to adjust aperture, shutter speed, and ISO automatically to achieve a balanced exposure. However, what the camera determines as "correct" is not always ideal from a creative standpoint.
Nearly all smartphones support automatic exposure adjustments.
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Automatic exposure can struggle in challenging lighting conditions, such as high-contrast scenes or backlit subjects. The camera may overexpose or underexpose the image depending on the lighting, leading to results that are not what you intended. This is where exposure compensation comes in handy. Exposure compensation allows you to override the camera's automatic settings to make the image brighter or darker, giving you more control over the final result. By using exposure compensation, you can correct the camera’s interpretation of the scene and achieve the exposure that best suits your vision.
Many cameras feature an exposure compensation dial (-3 to +3) or menu option to adjust image brightness before taking the shot.
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Balancing the Exposure Triangle
The magic of the exposure triangle lies in understanding how aperture, shutter speed, and ISO work together to achieve the perfect exposure. Adjusting one of these settings will impact the others, and it’s important to find a balance that allows you to achieve the look you want without compromising image quality. For example, if you want a shallow depth of field but there’s too much light, you can use a faster shutter speed to compensate for the wide aperture. Alternatively, if you are shooting in a dark environment and want to keep your shutter speed fast to avoid motion blur, you might need to increase your ISO to ensure the image is properly exposed.
In this image, a large aperture blurs the background, while a fast shutter speed prevents subject blur.
(Image Credit: Ian Schneider)
Each setting has an artistic effect on your image. A wider aperture creates a beautifully blurred background, a faster shutter speed freezes action, and a higher ISO helps capture scenes in low light. The challenge is to balance these three factors to achieve the intended creative effect while ensuring that your image is neither too dark (underexposed) nor too bright (overexposed).
Intentional underexposure can create an artistic look in photos.
(Image Credit: Pathum Danthanarayana)
For example, let’s say you’re photographing a dancer on stage in low light. You may want to use a fast shutter speed to freeze the dancer's movement, but this limits the amount of light entering the camera. To achieve proper exposure, you can open up the aperture to let in more light, but if that’s still not enough, you may need to increase the ISO. Each decision affects the final image — not only in terms of exposure but also in terms of depth, noise, and sharpness.
In stage performance photography, a fast shutter speed (say, 1/400s) is needed to freeze dancing movements.
(Image Credit: Maick Maciel)
Practical Tips for Mastering Exposure
Use Aperture Priority or Shutter Priority Modes: If manual mode feels overwhelming, try using aperture priority (A/Av) or shutter priority (S/Tv) modes. In aperture priority, you set the aperture, and the camera automatically adjusts the shutter speed for proper exposure. In shutter priority, you set the shutter speed, and the camera adjusts the aperture. These modes help you learn how one setting affects the others while still getting well-exposed images, making them excellent tools for building confidence in understanding exposure.
Aperture priority mode allows you to set a fixed aperture, while the camera adjusts the shutter speed and ISO automatically.
(Image Credit: Adil Ansari)
Use Exposure Compensation: In situations where the camera’s automatic settings don’t get the exposure quite right (e.g., very bright or very dark scenes), you can use exposure compensation to adjust the brightness to your liking. This is particularly useful when shooting in semi-automatic modes. Exposure compensation allows you to override the camera's suggested settings to achieve the desired brightness, helping to prevent underexposed or overexposed shots.
For silhouette photography, reducing exposure through exposure compensation helps achieve a strong effect.
(Image Credit: Levi Guzman)
Practice in Manual Mode: The best way to master the exposure triangle is by practicing in manual mode. You can manually set the aperture and shutter speed and leave the ISO on auto. Many modern cameras handle higher ISO values, like 1600 or 3200, with minimal noise compared to the film era. Additionally, noise reduction software has made it easier to eliminate any remaining noise in post-processing, so concerns over noise are far less critical today than they once were. Start by experimenting with different combinations in various lighting conditions to understand how each setting influences the final result.
Astrophotography often requires a high ISO (ISO 6400 or higher) to capture faint light. A tracker can compensate for Earth's rotation during long exposures, and special cooling equipment is used to reduce camera noise.
(Image Credit: Alexander Andrews)
Check the Histogram: The histogram is a useful tool for evaluating exposure. It shows the distribution of tones in your image, from shadows to highlights. A balanced histogram with no significant clipping on either end generally indicates a well-exposed photo. By using the histogram, you can ensure your images aren’t unintentionally too dark or too bright. Learning to read the histogram will give you more confidence in your exposures, especially in challenging lighting situations.
When the histogram peak appears on the right, it may indicate overexposure. If it's on the left, underexposure is likely.
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Bracket Your Shots: Exposure bracketing is a technique where you take multiple shots of the same scene at different exposure levels — typically one at the camera’s suggested exposure, one slightly underexposed, and one slightly overexposed. This technique ensures that you have at least one well-exposed image, and it can be particularly helpful in tricky lighting situations or when shooting high-contrast scenes. Many cameras have a bracketing feature that automates this process, making it easy to capture a range of exposures.
Exposure bracketing for sunrise and sunset shots helps expand the camera's dynamic range, ideal for HDR blending in post-processing.
(Image Credit: Artem Sapegin)
Use a Light Meter: Understanding how to use a light meter can greatly improve your ability to get accurate exposures. Most cameras have a built-in light meter, but handheld light meters can provide more precise readings, especially in difficult lighting conditions. Additionally, there are light meter apps available for smartphones, which, while often limited in functionality, can still be useful in a pinch or for quick assessments. Using a light meter allows you to measure the amount of light in a scene and adjust your exposure settings accordingly, ensuring a properly exposed image.
Sekonic is a renowned brand for light meters, a must-have tool for many studio photographers.
(Image Credit: Billy Freeman)
When the Exposure Triangle is Not Applicable: Light Painting
While the exposure triangle is fundamental for most types of photography, there are certain situations where its conventional rules may not apply. One such scenario is light painting. Light painting involves using a long exposure, typically several seconds to minutes, to capture moving light sources in a dark environment. In this technique, the shutter speed is kept very slow to allow enough time for the moving lights to be captured, while aperture and ISO settings are often adjusted to prevent overexposure. Unlike traditional photography, where achieving a balanced exposure relies on the interplay of aperture, shutter speed, and ISO, light painting focuses more on the creative manipulation of light during a prolonged exposure, making it less about balancing these three elements and more about artistic expression. The emphasis here is on experimenting with the movement of light, which often means deviating from the typical guidelines of the exposure triangle.
Aperture and ISO adjustments, rather than shutter speed, are used for creative light painting.
(Image Credit: Genessa Panainte)
Mastering the exposure triangle is essential for taking control of your photography. By understanding the interplay between aperture, shutter speed, and ISO, you can make informed decisions that lead to well-exposed and visually striking images. Each component of the exposure triangle influences both the technical aspects and the artistic qualities of your photographs. Whether you’re capturing the soft bokeh of a portrait, the motion blur of a waterfall, or shooting in low light without introducing excessive noise, balancing these three settings will help you achieve the desired effect.
Is a fast shutter speed necessary for stage photography?
(Image Credit: Ahmad Odeh)
Written By Jacky Lee, Founder of PSHKA.
