Exposure is the amount of light that reaches the camera sensor when the shutter button is pressed. It’s determined by three factors:

  1. Aperture
  2. Shutter speed
  3. Exposure index (ISO)


The aperture or f-stop is the hole in the middle of a camera lens. It controls how much light enters the lens, which affects exposure and sharpness.

Wider apertures (lower f-numbers) allow more light in, allowing you to shoot with a faster shutter speed and/or a lower ISO. They also have a shallower depth of field.

Smaller apertures (higher f-numbers) have greater depth of field. These can be beneficial for landscape photography.


Shutter speed

Shutter speed (or exposure time) refers to how long the physical shutter on a camera is open, exposing the sensor to light coming in through the lens.