ISO

In Digital Photography, ISO measures the sensitivity of image sensor. The lower the number of ISO, the less sensitive your camera is to light. By choosing a higher ISO, you can use a faster shutter speed to freeze the movement. ISO is one of three important settings on a camera. It's used to take a well exposed photo. The other two are Aperture and Shutter Speed. Shutter speed is the unit of measurement that determines how long shutter remains open as the picture is taken. The slower the shutter speed, the longer the exposure time. The shutter speed and aperture together, controls the total amount of light that reaches past the sensor. Aperture refers to the opening of a lens's diaphragm through which light passes. Another important part of ISO, is the exposure. exposure is the unit of measurement for the total amount of light permitted to reach the electronic sensor during the process of taking a photograph.