" Photography triangle "

An ISO ( international organization for standardization ) numbers tells how sensitive a film or sensor is to light. The higher the ISO no., the less light is required to produce an image , so you can make pictures in dimmer light. It is set and changed in the shooting setting menu.

the aperture adjusts the amount of light reaching the film or sensor. A large opening allows the most light to pass through the lens. The smallest opening lets in the least amount of light . It is located in the lens.

The shutter opens and closes to control the length of time that light strikes the light . Sensitive surface .