What is exposure? In photography, it simply means the amount of light to which the film or sensor has been exposed. The next question is how do we control the exposure? The shutter speed is one factor, the aperture setting is another factor. The creative use of the two variables aperture setting and shutter speed, gives us a way to produce artistic freedom and impart emotion and feeling. The controls require us to make choices and experiment with settings but they provide artistic liberty as we build our body of experience and knowledge.