Introduction to imaging

The importance of understanding light

As the sun rises in the morning and travels across the sky, the direction of light changes. This can be seen in how the shadow of a tree shifts throughout the day.

In surveillance applications it is important to keep this in mind. To avoid potentially blinding backlit situations, it is always good to have the sun behind the camera.

Clouds or bad weather conditions affect the intensity of sunlight, which will require changes to the exposure settings in the camera.

The time of day also affects the color of the sunlight, which changes from neutral at midday to warm, intense colors at sunrise and sunset. The color of the light is referred to as color temperature.

All of these light parameters will affect how images are perceived. Therefore, light direction, light intensity and color temperature all need to be fully understood and correctly handled in any surveillance application.

Exposure in sunny and cloudy conditions