Exposure triangle (aperture, shutter speed, ISO)

Exposure triangle (aperture, shutter speed, ISO)

The exposure triangle is a fundamental concept in photography that refers to the three elements that determine the exposure of an image: aperture, shutter speed, and ISO.

  1. Aperture: This is the opening in the camera lens through which light passes to reach the camera's sensor. It is expressed as an f-number (e.g. f/2.8, f/5.6, etc.). A larger aperture (smaller f-number) allows more light to enter the camera, resulting in a brighter image. A smaller aperture (larger f-number) allows less light to enter, resulting in a darker image.

  2. Shutter speed: This is the length of time that the camera's shutter is open to allow light to reach the sensor. Shutter speed is expressed in seconds or fractions of a second (e.g. 1/250s, 1/1000s, etc.). A faster shutter speed will freeze fast-moving action, while a slower shutter speed can be used to create a sense of motion in the image.

  3. ISO: This is a measure of the camera's sensitivity to light. A higher ISO value will result in a brighter image, but also increase the amount of noise (graininess) in the image. A lower ISO value will result in a darker image, but with less noise.

Balancing the aperture, shutter speed, and ISO is the key to obtaining the desired exposure in photography. By adjusting one element, you will have to adjust one or both of the other elements to maintain the desired exposure. Understanding the exposure triangle is essential to mastering the art of photography.