Exposure triangle

The exposure triangle, also known as exposure value or exposure value in photography, is a theory that governs how much light gets to your camera sensor. Three components make up the exposure triangle:

          • Shutter Speed
          • Aperture
          • ISO

Whether using film or digital photography, you must ensure that all three factors are in perfect balance in order to take a shot that is correctly exposed. Accordingly, if one element changes, the other two must as well.

Shutter Speed

The length of time the camera shutter is open during which the digital sensor or film is exposed to light is also referred to as the "exposure time." In terms of time, shutter speed is stated as follows: A shutter speed of 1/100 signifies that it was open for 1/100th of a second. Shutter speed enables you to stop or smear a moving subject.

Aperture

This is the size of the hole where light enters your camera. Your camera's lens will dictate what aperture you have, which is expressed in F-stops. A narrower hole results in less light entering the camera as the f-stop value increases. For instance, f2.8 permits 16 times more light to enter the camera than f11 and double that of f4. Aperture also influences the depth of field in your photographs, with bigger openings producing a shallower depth of field and smaller openings bringing more of the image into focus.

ISO

This is the value that represents how sensitive to light the sensor in your camera is (for example, ISO 100, ISO 200, etc.). The International Organization of Standardization, or ISO, is responsible for determining the sensitivity values for camera sensors. High ISO levels are advantageous for night photography since they increase your camera's sensitivity to light. However, boosting ISO might also result in an increase in digital noise in your photographs, so you usually want to keep your camera's native ISO level as low as possible.