Understanding exposure triangle – The most basic lesson

Home/photography tips, Tips/Understanding exposure triangle – The most basic lesson

One of the most essential requisites of photography is understanding the exposure triangle. A good grasp of this aspect can have a dramatic effect on the quality of your finished pictures. Exposure can either make a picture spectacular or ruin it completely. As a result, understanding the exposure triangle will help you build a strong foundation in photography , and produce some great and creative shots.

The three components of the exposure triangle include; ISO, aperture, and shutter speed.

While the ISO is the measure of a digital camera sensor’s sensitivity to light, the aperture refers to the size of the lens opening when a picture is taken , and finally shutter speed measures the amount of time that the shutter is open.

These three components work together to generate the exposure value (EV). This means that no single component can work in isolation. Trying to manipulate one of these three aspects will have a direct impact on one or both of the other components of the exposure triangle.

Understanding exposure triangle

Exposure Triangle including

1. ISO

This component of the exposure triangle controls the sensitivity of a camera’s sensor to light. ISO value is measured in numbers i.e ISO 50, ISO 100, ISO 200, ISO 400 , and so on. The higher the number the higher the sensitivity to light. Lower values means that the sensor is less sensitive to light. For you to become an experienced photographer , you need to understand the ideal ISO settings. A higher ISO allows you to work with less light but with a trade off. Higher ISOs such as 400 allow for less saturation and details but increased noise. Noise results from the random fluctuations in an electrical signal. Every time you increase the ISO level, the sensor’s sensitivity is doubled meaning you will need half the amount of light that reaches your sensor for the same exposure.

When working at higher ISOs, the image signal to noise ratio is relatively large. That means the noise will remain unobtrusive. At higher ISOs, the image signal tends to be close in magnitude to that of the noise, and as a result, noise enters the image.

Some of the situations where you might be required to use a high ISO include:

  • Indoor sports events: In this setting, the subject might be moving fast yet you have limited time to take the shot.
  • Low light and ‘no flash’ zones such as concerts, churches, and art galleries. When working in low light, you’ll need to use a wider aperture and the slowest shutter speed possible to stop action. At this point, your only choice is to increase the ISO.

Understanding how to take advantage of the ISO ensures that you are more comfortable shooting in different lighting conditions.

Wait a moment, you are reading “understanding exposure triangle – the most basic photography lesson. But you’re a beginner??? you should read Photography for beginners, it will shows you what you need to know before you wanna become a professional photographer or an amateur photographer.

2. Aperture

As mentioned earlier, the aperture measures how open (wide) or closed (narrow) the lens’ iris is. The component controls the amount of light that reaches the sensor of a digital camera. If you look closely at your camera lens, you will notice ring-like blades that open and close depending on the size of lens opening you want. The aperture setting is determined by several numerical values known as f-stop values. The standard f-stop values are 1.4, 1.8, 2.0., 2.8, 3.6, 4, 5.6, 8, 11, 16 and 22. The higher the f-stop value , the smaller the aperture. Narrower apertures (higher f-stop values) mean the amount of light that gets to the sensor of the camera is lesser .

Furthermore, a smaller aperture size gives a greater depth of view, allowing a deeper portion of a scene to be in focus. This is usually used to capture broad landscapes. If you want a larger depth of field , ensure less light reaches the sensor. On the other hand, a wider aperture(lower f-stop values) creates a shallow depth of view allowing for isolation of the subject.

Remember that adjusting the aperture by just one stop means you either halve or double the amount of light that gets to your camera’s sensor. Usually, most camera lenses are at their sharpest around f/5.6 or f/8. The f-stop values can be confusing especially if you are new to photography, but with enough practice you’ll familiarize yourself with the values and produce the images you want.

3. Shutter speed

The shutter speed measures the amount of time the shutter remains open when taking a photograph and therefore how long the sensor is exposed to light. For most photographers, this is the most important components of the exposure triangle. When you press the shutter button, you will hear a snapping or clicking sound. This is the sound that tells you that a photo has been captured.

The shutter speed is measured in fractions of a second. For example, if a shutter speed of your digital camera reads 1/200s, it means that your camera is exposed to light for two hundredth of a second. When the shutter speed is smaller fraction, the shutter door opens and closes faster. Faster shutter speed gives the sensor less time to collect light resulting in low exposure. Slower shutter speed allows the more time for the sensor to collect more light resulting in a higher exposure.

Using a higher shutter speed stops motion due to either camera shake or subject movement, allowing you to maintain sharpness. When the shutter is open, the camera is basically recording the position of elements in the frame; if one of those elements moves, the result will often be undesired blurriness.

Once you are comfortable with using the shutter speed, you can play around with your photos and make them come out more creatively.


A combination of the three elements that make up the exposure triangle; ISO, aperture and shutter speed results in an equivalent exposure value for a particular setting. Changing one of the three settings will definitely affect the others. While understanding the principles of the exposure triangle is not a difficult task, mastering the art may take a lot of time and practice. In fact, even some of the best photographers are constantly changing and experimenting with their settings as they go. Hopefully this article is helpful to you if you’re just starting out in your journey in photography.


Leave A Comment