Beecher's Handouts /

Exposure / 9 - Exposure Introduction

This section discusses exposure.

Definition

Exposure is the amount of light striking the sensor.

Three Controls

The amount of light is controlled by using:

1) ISO

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

2) Lens opening

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.

3) Shutter speed

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

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