What Is an Exposure Triangle in Photography?

If you’re fairly new to photography, you’ve probably heard of the term “Exposure Triangle.” This term refers to a little triangle that rules a good quality picture with a certain exposure level.
To master exposure in photography, you would need to know some basic information about the exposure triangle. So, what is exposure triangle in photography? This article will give you all the info you need.

What Is the Definition of an Exposure Triangle?

The exposure triangle is a term that describes the elements that correspond to how nicely the exposure of a picture is. These elements are aperture, shutter speed, and ISO.
To achieve a perfectly exposed photo, all three aspects of the exposure triangle must be in balance, according to the definition.
As you can see, the exposure triangle is critical for getting the most out of the scene you're taking to achieve your goals. When you photograph in automatic mode, your camera automatically balances the exposure triangle by adjusting the three settings.

The Three Sides of the Exposure Triangle

In order to perfect a picture’s exposure, one must learn the three sides of the exposure triangle. Understanding aperture, shutter speed, and ISO is the key to being a proper, professional photographer.
To understand the relation between the elements, you need to know how each element works first.


The aperture is the first side of the exposure triangle. It refers to the lens' opening; the wider it is, the more light the camera sensor will record.
A wide lens’ opening results in increased exposure. Conversely, as the aperture narrows, the image becomes less bright, reducing exposure.
A wide-aperture lens lets in more light, allowing you to utilize a faster shutter speed or lower ISO to achieve a properly exposed photograph. A narrow aperture, on the other hand, allows less light in, necessitating the use of a higher ISO or a slower shutter speed to compensate.
Another effect of the aperture is the depth of field. The larger the aperture, the smaller the concentrated area will be. Meanwhile, using lower apertures will result in a larger focused area. When altering the exposure triangle, this should also be considered.
While aperture is crucial in exposure triangle photography, it’s highly influenced by the following variable, shutter speed.

Shutter Speed

A camera's aperture opens when the shutter button is pressed. The shutter speed of the camera controls how long the aperture remains open.
The greater the shutter speed, the more light is captured by the camera sensor, and the longer the final exposure. Shorter shutter speeds, on the other hand, allow less light to reach the sensor, resulting in a less exposed final image.
Another consequence of shutter speed that must be considered when balancing the exposure triangle is motion.
Shutter speed, like the other variables of the exposure triangle, affects not only exposure but also other visual elements. Motion blur, for instance, is affected by shutter speed.
You can photograph moving things or shoot with a rapid shutter speed. Additionally, long exposures can be used to photograph stars, waterfalls, and rivers with the silk effect.
Fast shutter speeds, on the other hand, will produce crisp images. It will, however, allow less light through, making it unsuitable for darker images. When filming a video, the same issue occurs.


The exposure triangle's final variable is ISO. You can think of ISO as the digital sensor's sensitivity, although it is a lot more complicated than that.
ISO refers to the camera's ability to amplify the light it captures. The aperture of the lens and the amount of time the shutter is open are how digital cameras catch light naturally. ISO enhances the image's brightness artificially.
The ISO scale, like the shutter speed, is simple to comprehend. A shift of one division doubles the ISO and results in a one-stop increase in exposure. A half-stop reduction in ISO equals a one-stop reduction in exposure.
Because the camera captures clear shots only under optimal lighting circumstances, a low ISO value is good for the camera when there is lots of light.
Higher ISO values indicate that the sensor does not require as much light to achieve proper exposure. Low ISO values suggest that the sensor will need to gather more light in order to complete the exposure.
When working in low light, you're using the widest aperture and slowest shutter speed to gather as much light as possible. The only option, in this case, is to increase the ISO.
By increasing the ISO, you can work with less light. Excessive ISO, on the other hand, results in more noise and less detail.

How the Exposure Triangle Works

There is just one mathematically accurate exposure for any shot. However, there are hundreds of aperture, shutter speed, and ISO combinations that can be utilized to generate that exposure.
Thus, It's time to learn how to use the exposure triangle in photography so you can achieve the ideal balance and exposure in your photographs.
Understanding two major concepts—exposure triangle stops and exposure triangle balancing—simplifies the explanation of the whole concept.

Exposure Triangle Stops

A photography stop is a method of measuring light in which the amount of light hitting the camera sensor is doubled or halved.
For example, lowering the shutter speed from 1/4000th of a second to 1/2000th of a second increases the shutter speed by one stop, thereby doubling the amount of light.
On the other hand, lowering the ISO by one stop from 400 to 200 will cut the amount of light in half. Because aperture does not correspond to doubling or half the F-stop value, knowing how much a stop equals is more difficult.

Exposure Triangle Balancing

The basic rule of the exposure triangle is to create a balance. When all three triangle sides are equal, you'll get the correct exposure value, which is usually near zero.
According to this rule, if you change one of the triangle's sides, you must compensate by changing one or two of the other sides, always maintaining balance, which is the exposure triangle's ultimate purpose.
For example, if the exposure value is zero, and you want to increase two aperture stops, you must lower an ISO stop and a shutter speed stop or two ISO stops or two shutter speed stops. That’s to maintain balance and keep the exposure value at zero.
There is no rule about which setting in the exposure triangle should be adjusted first or which side of the triangle should be used to compensate. It all depends on the scene's lighting and the subject that's supposed to be captured.


The exposure triangle is an essential skill that needs to be mastered by almost all photographers to reach the perfectly exposed picture.
In order to achieve such a perfect balance of the exposure triangle, a photographer must know the definitions of the three elements that contribute to the formation of the exposure triangle.