What Is the Exposure Triangle?

Photographing with the exposure triangle

There it is: your new camera. A great reason to head out and take new photos. But how do you make sure, for example, that the exposure is always right while shooting? We'll explain how to do this in this article.

Aperture, shutter speed, and ISO?

Are these terms unfamiliar to you? Then it's time to briefly explain them before we go further into the exposure triangle.

Aperture

The aperture is the adjustable opening of the lens with which you determine how much light reaches your camera's sensor and how large the area of sharpness is. Depth of field is the depth in the photo that is in focus. With a large aperture, there is little depth of field — you select an area that is sharp, while everything around it is blurry. A small aperture means a lot of depth of field. This means that subjects in the foreground and the background are both sharp. The f-number on your lens indicates the aperture range of your lens.

Shutter speed

The shutter speed determines how much light falls on your camera's sensor. The longer the shutter stays open, the more light hits the sensor and therefore the brighter your photo becomes. In addition to controlling the amount of light on your sensor, the shutter speed has a second function. It also determines the motion in your photo: whether the subject is in motion (long shutter speed) or 'frozen' (short shutter speed).

ISO

The ISO value is the setting with which you can determine the light sensitivity of the sensor. This works very simply: the higher the ISO number, the higher the light sensitivity of the sensor. This also comes with a disadvantage, because it can also cause more noise in your photo. Noise is a lack of sharpness in the photo due to too little or poor light when you took the picture, which results in a so-called grain in your photo. By setting the ISO correctly, you prevent this.

How does an exposure triangle work?

An exposure triangle means that the three components (aperture, shutter speed, and ISO) must be perfectly balanced with each other. Then they form an equilateral triangle. When you achieve this, you've taken a well-exposed photo.

If you still want the photo to be a bit brighter, you adjust the shutter speed. This means the triangle is no longer in balance. Keep in mind, therefore, that you need to readjust the other side(s). Only in this way do you restore balance to your photo. For example: you've taken a photo but want to add a bit more depth of field, so you adjust the aperture. Don't forget to check the shutter speed, because it must be in proportion to the aperture in order to get a well-exposed photo.