What does the term ‘f-stop’ measure in photography?

The term ‘f-stop’ refers to the measure of the aperture opening in a camera lens, which directly influences the amount of light that enters the camera. The aperture is adjustable, allowing photographers to change the f-stop value to either increase or decrease the light that reaches the sensor. A lower f-stop number corresponds to a larger aperture opening, permitting more light to pass through, while a higher f-stop number signifies a smaller opening and, consequently, less light.

Understanding the f-stop is crucial for achieving the desired exposure in an image, as it affects both the brightness and depth of field. Adjusting the f-stop not only controls the amount of light but also alters the focus range within a scene. Therefore, the f-stop is a vital component in the exposure triangle, which also includes shutter speed and ISO, helping photographers balance these elements for optimal results in their images.