In understanding Exposure, there are 3 elements that we need to study. These three elements are closely related to light, how light enters and interacts with the camera.
These three elements are
- ISO: The level of sensitivity of the camera sensor to light
- Aperture: The opening of the lens when taking a photo
- Shutter Speed: The time the window in front of the sensor opens
The combination of these three elements is called exposure. Every change that occurs in one element will result in changes to other elements.
Today's cameras have sophisticated image viewing and exposure calculation capabilities that include information on a combination of Aperture, ISO, and Shutter Speed. Even some cameras today have exposure modes that are either Manual, Semi Auto or Automatic.