Beecher's Handouts >

Exposure >

Exposure is the amount of light striking the sensor.

The amount of light is controlled by using three controls.

ISO is a measure of how sensitive the sensor is to light.

The lens opening is an iris-like device in the lens.

By changing the size of the lens opening, the intensity of the light reaching the sensor is varied.

Lens opening is also known as aperture, f/stop, and rarely, diaphragm.

When the shutter opens, the duration of the light reaching the sensor is controlled.

Let's look at ISO, lens opening, and shutter speed.