Chapter 1:

• A photographer must understand the relationship between ISO (how sensitive the light sensor will be to light), f-stop/aperture (how much light is allowed to pass through the lens), and shutter speed (how rapidly the shutter closes, cutting off the incoming light).
• Any adjustment to one of these settings will impact the others. It is up to the photographer to set all three in balance, to achieve the desired depth of field, motion blur, and exposure.